In the FX channel, put a sine wave function on the pitch of the channel, then an automatic pitch corrector after that. It'll sound like your VCR is trying to figure out what speed that video tape is supposed to be played at.
Also, if you're using FL, routing the synth through two channels and having one with a very, very scratchy squeeze (I'm talking maybe one or two pops per note), run a randomized percussion loop through that, then cut off anything below a certain volume. That'll just give you pops to a beat. If you render it to a .wav or .mp3 file, then use it in a different song at the original tempo, it'll seem pretty random.