How about a simple catch-all "Off-Topic" subforum? If you have an IT section on a language forum there is no good argument against a recipe section and a sports section and a ... You get my drift.

However, looking at the General Discussion folder I think there already is such a thing. Hanna, I think in such a specific situation as your question about the WeTab it is OK to "misuse" a forum, in this case the German subforum, in order to find Germans. In all others the General Discussion folder has shown to be sufficient, after all I remember we have had an OS poll in there, Rocksmom asked questions about presentational software there and so on.