To be honest, not as much as I'd initially hoped.

- Fitting a USB interface is possible, but it's a bit fiddly, so not many got added.

- I ported OpenWRT, as a good Linux distribution, but I haven't used it for anything after! :/

- There have been some cool projects made by others though, like the zipitbot: http://justinbox.aresgate.net/html/make_page.php?n=zipitbot

Yeah. I have a terrible urge to get all these low-end machines and they inevitably are not terribly useful.

I did just buy a TP-Link 703n which seems pretty useful for a low-end box.