I recently used the live tracking feature of TF for some navigating on old mining roads. While it worked (now that 2.1 finally supports my POS Magellan GPS), I ran into a problem. I had tried the pan-around-to-cache-all-the-tiles approach to seeding my cache, but I apparently missed some crucial tiles. Zooming in or out didn't help, since I hadn't cached those tiles at all.
My suggestion has two parts: First, it would be nice if one could see easily what tiles are cached. Possibly overlaying the target grid onto a larger grid's images, so one has some context about what tiles are missing (e.g., show the 4M tiles, with shading showing the status of the 1M tiles).
Second, it would be *really* nice if TF allowed batch downloading of multiple resolutions and styles for a given area. That is, given this area, download all 1M, 4M, 16M, and 64M topos and aerials. Obviously, this could be abused pretty badly, but perhaps limits could be built in?
-- Mark