(på engelska)
For cheap entry-level 532nm green look at these:
Deal extreme 35mW 532nm module. Price: 57.20 USD - free shipping
http://www.dealextreme.com/details.dx/sku.10004
Aixiz 15mW 532nm module on Ebay. Price: 41 USD + 6.50 USD shipping
(possibly the same as the above one from DX)
http://shorl.com/tesulifryvobro
Aixiz 50mW 532nm module on Ebay. Price 65 USD + 6.50 USD shipping
http://shorl.com/stoprygratrafrifa
All these will reliably do 70 to 100mW when tweaked a bit.
The black one from Aixiz seems a bit better built.
I use the http://www.die4laser.com/dvd-rec/Die4Drive.htm
as drivers for mine.
I have used one of the ones from DX for about 40 hours at 75mW wih no degradation I can measure or see.
I have a BlueRay 405nm laser in my projector, the diode is cheap and can be found in a spare part for the Xbox360: http://www.psxboy.com/804_XBOX360-PH...aser-Lens.html
It can deliver about 150mW or so. You can propably combine two using the PBS-cube in the drive.
There is a groupbuy on the way for even more powerful diodes from 6X BluRay writers at LPF:
http://www.laserpointerforums.com/fo...m=1223438970/0
Lenses for bluray is a bit complicated, they need to be anti reflective coated for 405 or uncoated to work.
A standard clear acrylic lens from Aixiz or DealExtreme works ok but there is a another groupbuy on LPF for special 405nm lenses:
http://www.laserpointerforums.com/fo...num=1212842385
A really good red diode can be found in the Pioneer 112D och 115D DVD writers that can be found at almost every seller of computer parts.
The diode delivers 250-350mW with good cooling.
Two can be combined using a Polarizing Beam Splitter (PBS) for a 0.5W red!
Most people use a cheap Aixiz or DX 5mW red module as a mount for their more powerful homebuilt lasers:
http://shorl.com/dostaguguratre
http://www.dealextreme.com/details.dx/sku.5914
They only cost a few dollars each and are ok.
Sometimes you need to mount them in someting that dissipates a bit more heat, a bigger block of aluminium with a hole works.
You can also buy cheap glass lenses at Aixiz, they make a better beam than the plastic lens.
I have made my own mounts, it's not that hard but you need a 3.6mm drill and a M9x0.5mm tap that is quite expensive.

I have quite cheap 30k scanners from laserphoto in China:
http://www.laserphoto.org/en/company.asp
I believe that is the same brand scanners as lasershowparts have on their cheaper scanners.
The mirrors even reflect 405nm (BluRay) really well.
My dichros, PBS and mounts are from www.laser-wave.com, they have several european resellers, look at http://www.laser-wave.com/eContact.asp
Also, try to find a cheap laser power meter. I found a Coherent sensor board on ebay but they are all gone now. Some of my friends have bought this sensor (24USD, max 120mW) on ebay and are happy with it.
http://shorl.com/radrykukasudru Just connect it to a multimeter.
The same company has models up to 1W, http://www.bauer-electron.com/eby/eby1wlpm.htm