Many people seem to feel that Neville Longbottom is this generation's Peter Pettigrew, presumably because of their somewhat similar physical descriptions and, possibly, because Neville's cringing terror of Snape seems similar to Pettigrew's behavior with Voldemort. (Though, to be fair, it doesn't seem nearly as popular a theory since OotP.)
I've never liked this theory. I'll admit that I do have a bias in favor of Neville, since I truly like the character, but aside from that, I have two major reasons why I don't think it's true:
1. Neville displays a great deal more strength of character than Peter. In PoA Sirius says to Peter: "You always liked big friends who'd look after you, didn't you?" (US paperback p. 369). Additionally, in Chapter 28 of OotP (Snape's Worst Memory) Peter is described as watching James with awe and with his mouth open and whenever James catches his stolen snitch he gasps and applauds. When Sirius and James move to attack Snape, he watches with a 'look of avid anticipation on his face' and he laughs along with the others as Snape is tormented.
There's never been any indication of Neville having this sort of personality. Although he is friendly with both Ron and Harry, and relies on Hermione for help with his schoolwork, he is not close to the trio and there's no indication that he tries to be. He does not fawn over Harry, nor does he seem overly impressed by him. He is never shown participating in the teasing/tormenting of others, nor is he shown to enjoy watching when others do it. Most importantly though, he has the courage of his convictions and when push comes to shove he does what he thinks is right even when he knows he can't succeed. This is absolutely the polar opposite of Peter.
2. Neville despises Voldemort and the Death Eaters for what they did to his parents. I can't imagine any scenario in which he'd willingly join them. During the fight in OotP (Chapter 35) he was willing to die to protect Harry and the prophecy, whereas Peter plainly states in PoA (Chapter 19) that the reason he joined Voldemort was because he was afraid Voldemort would kill him if he didn't.
So, if Neville isn't this generation's Peter, who is? Based on a comparison of schoolboy behavior, I think it might be Colin Creevey.
Colin seems to worship Harry in a way similar to the way Peter worshipped James. The situation isn't exactly parallel, because Harry and James aren't exactly parallel; Harry is not one to enjoy the fawning attention of a sycophant and doesn't encourage Colin at all -- discourages him, in fact. (Can you imagine how differently 15 year old James and Sirius might have responded to an adoring admirer with a camera?)
In Chapter 7 of CoS, when Harry resigns himself to explaining the rules of Quidditch to him, Colin is described as "tripping down a couple of steps because he was gazing open-mouthed at Harry." (US paperback p 107) In that conversation he's described as speaking in awe and breathlessly. Later, when he's photographing the team at practice he calls out shrilly to Harry, and is 'dancing alongside them' as Harry and Hermione help Ron to Hagrid's. In fact, except for the time he's petrified, whenever we see Colin, he is so focused on Harry that pride and dignity go by the wayside, much like it seems to when Peter is with James and Sirius.
I can't think of any scenes where Colin participates in tormenting other students, but I think this may also be due to the differences between Harry and James. Harry doesn't do it, and if he sees it being done he's more likely to stop it than to laugh. However, if Harry were the sort of person who enjoyed tormenting others, it's not very hard to imagine Colin right there laughing and supporting him. When Ron's wand backfires and he's belching slugs, Colin shows a marked lack of empathy; he is 'fascinated' and his focus is clearly on getting good photos rather than helping Ron.
So, getting back to Neville, I think if he is this generation's anybody, it may be his father, Frank Longbottom. It will be interesting to see what the next books reveal about the relationship between the Potters and the Longbottoms. Clearly they're linked by the prophecy, as are Harry and Neville. We know they were somewhat equivalent colleagues of the Potters, as both couples were pictured in the old photo of order members, which so far seems to correspond with Harry and Neville's relationship as students and pre-Order members, but not extremely close friends.
I'd love to know what folks think about this -- do you think I'm right? Wrong? Crazy? Has the fandom already figured this out and I'm out of the loop again??