When looking at names for a .mobi extension (if you really want to get into that) remember that since this extension is relating and designed for a pocket sized mobile phone then try and keep the length of the domain to a minimum.
Typing Traintimetables.mobi on a phone keyboard would give most cellphone users karpal-tunnel syndrome!
When the .mobi extension came out my group just ignored it since we already have our .coms that already have a mobile website...for example...we have
wap.giantweed.com which works just fine as a mobile website since it only works for internet enabled phones and it is more brandable as a .com than a .mobi in my opinion.
The bottomline is to make domain names designed for the mobile market to be short to reduce the number of keystrokes required.
The fact that .mobi has 4 keystrokes and .com has three keystrokes is already an issue for me.
Good Luck!