Hey there Amanda... i also tend to have problems staying motivated and sticking with things. This diary is perhaps the only reason that I'm still on my diet after four months!!! And it's exactly for the reasons that the others have said above. It makes such a difference when you get the encouragement from others. Just signing on once a day and knowing that other people are going through this and that they have left you this great little note makes my day and makes me want to try harder.
It also really helps to post online, even on your bad days, because that way we can encourage one another and point out things that could be healthier, etc. For example, I didn't realize that grapes were so high in sugar and weren't that great to have for a snack - but reading someone's diary, I found out that information, and so now i'll try to have them less often and eat a snack with more fiber instead.
Good luck here! and I hope that you find this as wonderful of an experience as I have!!!!