I want to use my second N900 as a mobile WiFi range extender. At his moment I use an Android app named fqrouter that does the job on my Nexus 7 tablet. I wonder if the N900 also can be used a an WiFi range extender. I do use qtmobilehotspot for 3G internet connection sharing but this application doesn't support the share of an existing WiFi internet connection. Can anyone tell if this can be don on Maemo or an alternative Linux system on the N900?

I don't think it's possible because the N900 wifi chip (firmware) does not support Infrastructure mode (only Ad-hoc), so I think regardless of the OS it won't work.