Subject line says it all... Like half.com for books, I'm aware of a few sites that exist that deal in things in the mp3 player family and such... But I don't know how to locate said sites. I haven't Googled this because I'm also aware of scams, and I'm looking for a reputable site, preferably one that has been used by our members here without issue. Can someone help?

oh oh
if you are in the us
go to Microcenter!

http://www.microcenter.com/

really good deals

In the US you can try Frys.com or bestbuys.com and Amazon does sell electronics.

Well, if you are looking for components, my friends tend to do their shopping at www.newegg.com .

http://www.tomshardware.com/

Here you can find the lowest prices and read reviews. They are pretty good I've heard.

Why don't you just use the site of the brand of mp3 player your using, they should sell them online there.

Perhaps a good resource for you would be www.resellerratings.com
They have ratings on pretty much every online store in existence as well as products. The ratings come from the people who use the stores, and they are very dependable. For example, Newegg has a lifetime rating of 9.7 out of 10 with over 7300 votes, so it's a good indication that it's a good store. They also rate in six month increments, so you can see if a place is going downhill. I've used bith Resellerratings and Newegg extensively and like them both.
Anyway, check it out and see what you think...

Newegg.com is a great place and has fast shipping. They back up their products with good service.

www.zipzoomfly.com is another good one. I've personally used it for components for at least 4 computers(everything but the case/monitor). They offer free 2nd day shipping on most things, and are really good about returns if there is a problem.

Well, I'll echo the zipzoomfly and newegg suggestions. We've used the former and heard good things from friends who use the latter.