If you want to try something really wacky, reverse your clip as described in the posting above. (I'm assuming you're not just looking for a reverse-gated reverb.) Practice saying it backwards by imitating the backwards recording. Then toast that and re-record the clip in the regular manner but saying it backwards as you've practiced it, and then reverse the clip so that it's forwards again. Follow? Basically the result is you've reversed youself speaking backwards so it's forwards again. It will sound totally weird yet familiar, sort of like an alien trying to speak English (sure we've all heard that lots of times). If you watched Twin Peaks and noticed how the dwarf talked, that's how they did it.