@SectorSeven: Have you tried the freeware program Audacity? Make sure you download all the plugins. You can then use the Generate and Effects menus to create a bewildering variety of sounds.
It's almost like painting - if you do your painting digitally with a selection of naturalistic and user-definable brushes, using, say, Painter or Paint.NET - the latter is free to download and use. The only difference is that Generate lays down the "paint" (raw sound), then Effects messes it around, distorting, layering and modulating it.
Set aside an hour or two to play with different effects, and I'm sure you'll see what I mean.