Since I didn't have a decent data-plan when I started programming this, it tends to cache everything possible (while updating data on a background).
You can also choose to use AGPS, cell-tower-positioning (since the N900's GPS seems to suck a bit), or use the locations of your last checkin as a reference for searches/etc, whichever is the most convenient.
It's still "under development" and all present features work fine. The most notabe issue is the lack of loading screens - the UI just freezes for a few seconds while it downloads data.
Of course there's still lots to do, like finding friends, tips and comments.
Feedback if greatly welcome, as are bug reports. I'll set up a website soon, and list known bugs, and wanted features, etc.
Just click here to install it!
Also, be sure to update the image cache on your first run, and be sure to do it over wifi. This'll make save huge amounts of times in searches, since category icons don't need to be downloaded on-demand. (They're cached anyway when downloaded on-demand, but you don't want to be waiting for images to download while searching for nearby venues).