I noticed your post on the 'I want to build a laser' thread, I can build a blue one for ya but I'd recomend for your first laser you buy one from ebay, I buy them in bulk for my friends so I get a shipping discount but even without the discount they're really cheap (Typically less than £10 if you search right)
I own a green version of the typical blue one and they're pretty good quality, not only that but they costless than the PHR-803T diode used in them!!! PM me if you want a link to one on ebay or if you still want one custom built =]