I used to, but it got too expensive. Every once in a while I'll buy a pack just for fun, or a card or two at a shop because I decide I like the picture or something; or once in a while I'll buy one of those big plastic packages with 100 cards or so they have at department stores just to look through them. But if I were really going to be a collector, I'd need a lot more $$$ than I have available now.
I hate to be one of those people who says, "Why can't it be like it was in the good ol' days?" but it really blows my mind. When I was a little kid and started collecting the 1983 Topps cards, you paid (IIRC) a quarter for a pack of 10-15 cards. These days it's more like 2-3 bucks for a pack of five or six cards. And then on top of it, you'd have to be really lucky to get a complete set for that year just by buying packs with all the inserts, etc.
The cards I do have, though, I'm rather proud of. Back in the late '90s, when eBay was just starting out, I bought several big lots of Patriots cards from guys, so I think I have at least one of just about every card from the late '70s into the early '90s. Going through those cards is about the only way to even learn about some of these long-forgotten guys who no one even talks about anymore. Garin Veris, Hart Lee Dykes, Ray Agnew, Tommy Hodson, Hugh Millen, Pat Harlow.