I frequent almost all the local 4x4 offroading clubs and forums and actively take part and mod in a few I like. Also frequetly visit a few other expat ones. Also member of quite a few Land Rover and Range Rover tech Forums, activity varies from very active for a few weeks to not logging in for months. Was a member of few Jeep and lexus forums which I don't visit anymore. Also active in a N.American general forum and I'm sure there are few I am forgetting a few. Ah yes there is also a cool offroading arabic forum with a lot of very good "eye candy" which is awesome for a petrol head like me
All in all there are quite a few cool places to hang out. Locally Dubai Forums is the best general forum out there. But offroading, 4x4's and modifications are my main thing online.