Making a portable wouldn't be easy. If you wanted to do a DIY job though, you can get 808nm diodes for dirt cheap. A Chinese 2W c-block will run you <$100, but that leaves you with the task of heatsinking, collimation, and a driver. A task that can be pretty intimidating if you don't have ample machining gear as well as an elementary background in electronics and optics.
If you want a ready-built unit, I think I pretty much offer the best deals around. I have a >450mW pen package w/goggles in stock available in that link Spyro posted. And if you have the MORE POWER! bug, I have some 500-950mW heavy duty packages w/goggles in stock here: http://www.laserpointerforums.com/forums/YaBB.pl?num=1198960204