Yet again, I grew tired of doing the same repetitive task, over and over and over. This time it was Auction searches, so here's my answer. Now, any time you do an Auction search, you can save that search into a FuBar-accessible alphabetized list for SUPAR-EASY ONE-CLICK AUCTION SEARCH-O-RAMA!
Each saved search stores the name, level range, rarity, and usable items fields, as well as the state of the filters nav, so you can fully replicate those favorite searches, over and over and over.. and over and over, and over..
If you have the FuBar tooltip detached, it will auto-hide when you're away from the AH. There are a handful of customization options for display, and you can rename and delete any saved searches.
I think this addon is pretty self-explanatory, and should be extremely useful if you do a lot of AH searching. It requires FuBar, and should co-exist just fine with other AH addons like Auctioneer.
Also, thanks to ckknight and the guys in #wowace for their helpful advice!
Note: Because of the way FuBar tooltips are currently handled, the detached tooltip might appear behind the AH frame. If that happens, you'll need to either A) add enough searches to the tooltip to make it grow large enough to be dragged, or B) use an addon like MoveAnything to move the AH frame. (I've asked ckknight for detached tooltip frame strata control)
20003.003 - fixed a minor bug, no functionality changes
20003.002 - fixed a minor bug, added optional "Text" column to the tooltip, the ability to sort the tooltip on any column, and a "Reset auction window" button
20003.001 - initial release