I need some science fair project ideas for a 7th grader. I already checked tons of websites, but there is nothing that I like. Any tips,or ideas?

Studies that correlate behaviors are always interesting, and involve only a moderate amount of effort. I did one when I was that age about time spent playing video games vs. amount of time it took to do a puzzle-type task. If your 7th grader likes to interview people, a survey that asks about two behaviors might yield some correlations (how many hours of TV a week vs. grade point average). You make a nice looking poster and pick a topic the student is actually interested in, and it can be pretty fun (for a science fair, anyway).

The first thing that popped into my head was magnetic levitation. Both cool and practical. In my humble, geeky opinion.