If the charging is anything like the Parisian Velib, then the charges would probably become exorbitant for this sort of jaunt.
Up to 30 minutes is free, then up to one hour costs 1 €. It goes up quite rapidly then, until you reach the up to 20 hours point, where the charge is 151 €, which is basically the same as the deposit that you pay on the bike. This is all from Wikipedia, and it's not clear if you get charged this and the deposit if you fail to bring the bike back. Either way, a trip to Brighton and back would be expensive, much more than the train fare.
If it didn't cost too much, I'd be up to try it, but I suspect they will want to discourage long hires.
Of course, you might be able to get the organisers to wave the fee in return for an advertising stunt, which might go down OK. Pretty much everyone would win; good advertising for the scheme (look, the bikes aren't that bad, you can cycle them to Brighton), we get to behave like nutters, and even Simon gets a bit more advertising for the FNRttC, not that he seems to need it now!
