Voice Amp alternative....?

I'm getting to the point with my costume, where I am starting think about getting a voice amp. I know The Radio Shack amps that all the TK's and Fett's use, but I heard that they were disscontinued, and they are nearly impossible to find. What has everyone been useing?

Actually I just bought mine last month on E-bay --- the discontinued Radio Shack one I mean... so they're out there if you look.