I just found an fun feat in Dungeonscape for Factotums. It's Undermountain Tactics, requiring that you're a Dwarf or Gnome (or BAB +6 and Knowledge Dungeoneering 2), so it's extremely easy to get as a Whispergnome anyway. It's the first maneuver that's so great, called Stair King. Any time you have high ground over your opponent (Greater Floating Disk?) and hit your opponent twice in a round, they have to make a Balance check (DC 10+Str modifier) or fall prone. They can forgo a move action next round to auto succeed... but that's irrelevant, because just like Grease they're balancing and thus flat footed. Thus, at higher levels, as long as you can hit twice, your opponents are always flat footed against the third and subsequent attacks. Combo with Blurstrike to flat foot them on the first hit as well. Great for any TWF Factotum who can generate lots of hits.
JaronK