What does everyone use for a co2 diffuser, just set up a DIY Co2 unit, and purchased a cheap glass diffuser off of ebay, will be here in a week. Right now I just have a green air stone on the bottom of my airline tubing. What does everyone else use and recommend? Any thing that will help dissolve the co2 a little better? Or DIY diffusers?

glass diffuser needs about 7-10 psi to work properly. DIY Co2 unit will not produce that pressure.
You can read in this link hoe to make DIY Diffuser.
http://www.aquaticplantcentral.com/forumapc/diy-aquarium-projects/72381-diy-diffuser.html

I have a glass diffuser set up to two DIY CO2 bottle and it works fine. I replace the bottles once a month.

Probably one of my favorite DIY diffusers is a chopstick, just shove a chopstick into the airline tubing... produces very fine bubbles IME. I got rid of my bamboo and got a good old bubble ladder instead, works a tiny bit better.

Another option would be a wood airstone diffuser generally used for skimmers... but they work the same as a chopstick and cost 4 bucks each

Midway, we've got them for 20 bucks each...
a bit pricy but it's worked great for me, think I might readapt it with that bamboo skewer idea daniil linked to
direct a tiny stream of bubbles into the bubble ladder seems like alot better than big bubbles... hmmm

I swear... I think everyone was there on saturday lol... they're above the planted display tank, the 75 gallon acroos from the bubble tank.