For more ideas on making it yourself try googling "DIY Live Rock"
If you want critters and coralline then you will still need to add a piece or two of live rock to seed the concrete rock. Otherwise you can just use a raw shrimp to cycle the thank and the bacteria you want will find its way into the tank naturally. Alternately, for coralline, you may be able to talk a local aquarist into scraping some coralline from their own tank and seed your tank with it.
Hope this helps
AquaC Remora Pro
140#s Live Rock from LiveRocks.com
Frogspawn, Hammer, Zoos, Leather Frag, and Xenia and Green Star Polyp frags from fishfreek and Alarmguy66, Thanks!
Member of the Unofficial A-Team
You can take dry base rock and put that in your tank. Take a couple raw shrimp and drop them in the tank and let them decompose. Beneficial bacteria will grow on the rock to combat the ammonia spike which is what makes rock "live." In time your tank will be cycled and ready to go.
It depends on what you consider live rock to be. If you think it is porous rock with beneficial bacteria on it...then yes. If you think live rock is rock containing life representative of that found on a reef...then no.