I would highly recommend the HCO Scoutguard SG550, I currently own 2 of them and I couldnt be happier. Very small, quick trigger, and awesome pics & even videos.

I would advise aggainst the Moultrie I40 if its a new 2008 model. I owned one about a month ago and it was very slow to trigger. They are better for monitoring feeders and not setting up on a trail. The 2008's have gone backwards in terms of trigger speed with a very slow 2.5-3sec trigger, if you can get ahold of a 2007 it is quicker but even then IMO the Scoutguards are more superiour.

Look Joe up of Beebusyoutdoors, he makes it around on here and sells the scoutguards
http://www.beebusyoutdoors.com/gasumoca.html