Should I get the iPhone 4 with the 32GB or the 16GB?

I currently only have the iPod nano and I have just a little over 300 songs on it because I tend to delete songs after I get bored with them. I do like taking pictures but I never record things. I have the EnV Touch and I absolutely hate it and I am now eligible for an upgrade. (thank God) But I know I want an iPhone but i'm just not sure which one woud be best for me because I know that I will be on the Internet all the time and I know i'll get apps but I will most likely delete them once I get bored with them. I don't like my phone to be cluttered with useless things. So, any help? Thanks :)