Thanks for the suggestion. Isn't it true that I can do the same with some Linux scripts? I think I've read something like that in another thread. I'd prefer that approach, since I don't really trust arbitrary websites. It might secretly remember the private keys of the generated addresses and its operators might decide to cash out as soon as a certain amount of money is stored on addresses generated by them.
Anyway, I think this still requires a patch in my Bitcoin client, so that I can later import the private key.
I updated the code for 0.4 but never released builds since I didn't perceive any demand for them. The code is now updated for the 0.5 qt gui so once 0.5 is officially released I'll release builds with my patch as well.
I don't need builds; please give me an URL for the source code of the version 0.4 patch. I'll give your code a quick security review (so hopefully it won't be too large) and then I'll compile my own client.