The Tap-a-Draft system has been out a while, uses standard CO2 "sparklets" available anywhere, and has even been adopted by the bigs (thread linked says they've licensed the system from Sturman BG). The trouble with these things where I am concerned is refrigeration space. Don't have it, not gonna get it, so this is right out.
“Malt does more than Milton can / To justify God’s ways to man”
-A. E. Housman (1859–1936). A Shropshire Lad , 1896.