In the 7th book, it says that only the seeker can touch the Snitch, even the maker wears gloves (because the Snitch has flesh memories). Why is it in Harry Potter and the Sorcerer's Stone, Oliver Wood was able to touch the Snitch?
That is a very good question. I'd also like to point out that, in OotP, we see James playing (without gloves) with a snitch.
I was going to suggest that maybe they have two snitches: one for practice and one for the game. But, Wood tells Harry (when he's teaching him about Quidditch) that they can't practice with the snitch because "it's getting too dark" and they "might lose it." If it wasn't a real snitch, it wouldn't be such a big deal if they lost it, so it can't be that.
I think it's just an error on JK's part. I don't think she had all those little details of what she'd put in the earlier libros when she sat down and wrote the seventh one.
Well, in Chamber of Secrets, they dicho that the balls were all kept under key in Madam Hooch's office (I hope I got her English name right, sorry if I messed it up). That means that teams must have other sets to practise, and when there's only 1 seeker on the court, there won't be any arguments about who touched it first. So really, they must be built simpler. Maybe the practise snitches don't have flesh memories.
It could be a snitch that he'd already caught- maybe he played Quiditch with his Dad o cousin inicial and he was stuck as seeker- whatever.
And as for James; it could be his own snitch, o he pocketed it from the Gryffindor practise set. Maybe he played like Ginny; he was seeker before his prefered post.