If you plan on making more games, then you could also consider making mailing list and letting them have this game for free as long as they join that mailing list.
That would mean that when next game comes out, theres lots of people who already know your previous game, and if they liked it, are potential buyers for that new and next one and next one and...
and al lyou need to do is send them a message and you get hefty amount of sales at once.
And not only that, but you could also use it to manipulate some Iphone stores. Say you release a new game, then when it gets to that Iphone store, instead of selling it yourself, you send your mailing list a message that now this game is available from http://www.iphonestore.com/newgame
and suddenly you might see that your new game jumps to number one spot on currently most sold games chart, which of course can be used very effectively for marketing and stuff (ie. contact games magazine and tell that this game is number one sold game at iphonestore.com, perhaps you like to make aastroy about it) and even alone already propably generates lots of sales since people easily check number one sold game when they check games.
Also, Now these Iphone games are still pretty new thing, so people might be interested enough to get a commercial game and join mailing list at this point. But 2 years later it might me much harder already since people might have got used to them already.