Also, a comparator or two could be useful for screwing around with timing. You can use them to extract gates from modulation signals...say you've got the comparator threshold at around +2V, and there's a slow LFO being fed to it. When the LFO's output exceeds that threshold, the comparator will fire off a gate, and the gate stays on as long as the incoming modulation signal stays above that. Combined with some Boolean logic, these are great (and simple!) ways to add some additional conditional logic behavior to the fray.