Eva Longoria and Kevin Smith Rockin' Around the Xmas Tree ... Lot

Forget the Walk of Fame -- if you wanna go sight-seeing for celebs, your best bet is gonna be Hollywood Christmas Trees, where people like Eva Longoria and Kevin Smith showed off their famous mugs.

Our Xmas tree sources tell us ... Eva came down to the Hollywood lot with the whole family to pick out a 9 ft. Nordman Fir ... she then had it dropped off to her Hollywood Hills home ... and we're told she left a pretty nice tip too.

Jay and Silent Bob -- aka Jason Mewes and Kevin Smith -- also made an appearance. Jason picked up a Noble Fir with some buds, while Kevin brought his whole fam to find a 9 ft. Douglas Fir.

And finally, we're told Sean Kingston actually sent his mom to do all the heavy lifting ... asking her to pick up a 9 ft. Nordman from the famous lot -- but in a classic Christmas moment she had some trouble getting it to stay on top of her car.

All in all, the trees set the celebs back between $80 - $130.