all good advice above
it will be very difficult though
its very hard to get thru to right person, get right price , even hear back when you have a great .com, .co.uk tbh
chances are at this stage even people who should have heard of .mobi in IT depts, haven't, and general public by and large haven't either so i wont say dont try, but ur email will probably be spammed
the reality is the same for 99% of domains in the simple sense that they will come to you
if someone makes up their mind they want a domain or need it and know a bit more knowledge about 'our world' than most in their field then you have a chance of an enduser sale
same way if you have a busy/successful site, advertisers find you and pay well, rather than taking crap from adsense
edit: speak to mjnels or egnited
thay have approached endusers and sold quite a few .mobis for good money