Is there any app out there that will trigger different .wav or .mp3 files at the push of a button?

For example. Sometimes I have pocket tunes open and a playlist with really short .wav files of crickets chirping, audience laughter etc. I'll cue them up and hit play when someone makes a good or a bad joke for example.

Of course, this would be much quicker an easier if I could just hit "c" for chirp and "l" for laughter.

The other thing I was wondering is if anyone has seen an mp3 player with any sort of pitch control functionality? I'm a DJ, and I've hooked my treo up to my mixer before, but i'd love to actually beatmatch by speeding up or slowing down my mp3s.