Fresh silicone glue may work great, but this is even better. Superfix from Casco.
Except for Scandinavia, I have no idea about the availability of this compound in other countries.
It's expensive, around 20-25 US $ for 300 mls, but worth it.
It's a non-toxic, doesn't smell, tough to get off your fingers, doesn't take any solvents, flexible and easy to cut
when hardened (remove crossover components for tweaking).
It probably contains a lot of latex (natural rubber) for having all these characteristics.

My Router guide

Click images to view large

The guide was bought on eBay from Germany: http://stores.ebay.de/weyher-holztechnik

As can be seen from the pics, the guide was modified as the pin (4 mm screw) is too large and un-handy for precision routing. I shortened the alu bar and inserted a 2 mm hard steel pin (concrete nail). The large handle on top was also omitted as this prevents routing very small holes.

Flanging straight vents made from ABS plastic:

The pics below are hopefully self-explanatory.
A number of vents are made from ABS plastic and usually requires to be cut to target length.
The outlet of the tube is already flared and after cutting to required length, the inner opening may
be given the same treatment simply by heating the end of the tube with heating gun.
I run my B&D heating gun at highest temperature and hold it 5-7 cm from the end of the tube while
slowly rotating the tube. When the tube opening starts softening I push it towards the bottle shoulders
and continue to rotate while pushing. When done I hold the flared end towards a piece of MDF while
cooling and you may add cold water to cool faster.

Soldering tag strips:

This is a question I've had many times: Where do you get the soldering tag strips used for the crossovers?

These come from RS-Components and you have to order from a shop dealing with electronics. rswww.com homepage
Item 433-775, approx. 2-3 US$/ea. Minimum is 10 pcs.

UK:
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=0433775

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=0433781

Getting these soldering tag strips in the US has proven quite a challence for a few and Robert/US came up with this information:

"connector, lug type terminal strip"

http://www.alliedelec.com/Search/ProductDetail.asp?SKU=750-6635&SEARCH=&ID=&DESC=56A&R=750%2D6635&sid=47801A004136617F#
from Allied Electronics: http://www.alliedelec.com/default.asp

However, only available in rows of 8, but very useful it seems.
Thanks to Robert for the information.

Bitumen pads and damping materials.

Bitumen pads (the black sheet) available here in Denmark at Harald Nyborg shops. http://www.harald-nyborg.dk/templ.asp
The pads have #01389: http://www.harald-nyborg.dk/merinfo.asp?varenr=01389&n=10

(the black sheet is 4 mm bitumen pads)

10 mm polyester foam bought in shop selling stuff for pillows, mattresses, etc.
Actually we have a "foam shop" , Jysk Skum, here in town, Aarhus/DK. Jaegergaardsgade 77, 8000 Aarhus C. http://www.jydsk-skum.dk/

Green felt material bought at car accessory shop. For those living in Denmark you can find the green felt at Jari Autosport:
http://www.jariauto.dk/shop/terms.html
Search for "grøn filt" and a local shop - or order on-line.

Mail from Michael:
I have found an American product that seems to do the trick. (See attached .pdf file.)  It is a modified asphalt product with a glue backing and costs only $42 for 111 square feet.   Please note that it is designed to be applied with high heat.  I have successfully applied it with a modified professional heat gun.  However, due to hazard of fire the membrane should really go on the panel before the cabinet is constructed.
I recently found that it can be more easily applied with contact cement.  If applied this way, the cement should be applied to both the non-glue side of the membrane and the panel, allowed to dry, then mated.   The best method is to bond two membranes; that is, heating and sticking together the glue sides of two membranes. This membrane is then contact cemented to the panel.  Of course this doubles the weight and thickness of the new membrane but it really increases the effectiveness of the damping of 19mm MDF.  I have tested it with an accelerometer and Clio and the results are impressive.    Before I forget, a single 4mm layer seems adequate for cabinet thicknesses up to 12mm.  I plan to test thinner cabinets with doubled members later.   Regardless of the application method chose, staples should also be used to provide a mechanical connection that protects the glue join.   I hope this information will be useful to you or others. 
Download file here. gif image/94KB

Thanks a lot to Michael!

PartsExpress
- has some bitumen pads in stock:
http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=268-010&CFID=10084208&CFTOKEN=94265725
This is mineral-filled asphalt dampening sheets, probably the same as those I can source here in DK.
Item #268-010 (10"x10") or #268-015 (29"x32"). These are only 0.07" thick = 1.8 mm, but you may use two layers.

More on bitumen:

For the last few years, I have used bitumen pads sold by Solens in Montreal.  It looks like the same that you are using.  Here's the link in case people ask you:
http://www.solen.ca/
My best regards,
Alain, Canada

Thanks, Alain.

Comments on damping materials from Kim Bond/Australia:

Some suggestions you might like to consider:

Polyether acoustic foam (see for example http://www.acoustop.com/pdf/161.pdf is very effective at absorbing frequencies above 300Hz (over 80% absorption) and gives excellent results in bass reflex cabinets. It can obliterate higher frequency standing waves and is very effective behind mid-range or full-range drivers, where it minimises high frequency reflections back out through lightweight cones – a little goes a long way.

Instead of bitumen pads, try constrained layer damping used in cars (see http://www.dynamat.com/technical_specs_dynamat_xtreme.html for an example) to damp critical enclosure panels. It is more expensive than standard automotive bitumen pads but thoroughly effective and, again, a little goes a long way.

Finally, good old wool. Carded wool is best, after the carding combs have teased the raw fleece into long, flattish strips. Hobbyist spinners and weavers know all about this stuff and are often happy to help. It is cheap too – and need I say that a little goes a long way?