I think it might have been mentionned in another thread, but this is so cool that I'll share it here:
Put a single cycle waveform in a flex machine (which, of course, can be as complex as you want - for instance I took a buchla FMd waveform which is far more complex than a single sine wave).
In the ATTR menu, set the loop to ON (that, I'm sure) and the timestretch to OFF (That, I'm not sure - not in front of the OT at the moment - the idea is that the sample must loop but not stretch to the BPM). Be sure that the start and end points in the TRIM window are at zero crossing points.
Adjust the Attack, Hold and Release parameters in the AMP section. You now have kind of a wavetable synth to play with. P-lock the pitch parameter in the playback menu.
What's incredible is that single waveforms take about 5kb to 10kb each. I loaded 600 waveforms of classical analog synths for a whopping 28mb on my compact flash card.
EDIT : oh and then you can p-lock Flex machines per step for different waveforms on each step...