Should I sell my Canon 18-55mm after buying a 17-40mm L?

Like the title says. I recently upgraded from a Nikon D5000 to a Canon T3i with the kit lens. Just ordered a 17-40mm L lens and I was wondering if my kit lens is worth keeping?

Added (1). Wow thanks for the quick responses! Didn't expect to get so many. As for selling the lens I'm fully aware everyone has it, I just really hate keeping things if I don't need them, so I really don't care what I make off of it. I just Really don't want to keep it if I don't have to. Anyway thank you all, this helped a ton.

Added (2). I'll just keep it around a little longer then and see if this "weight" issue with the 17-40mm is going to bother me.

Not really, at least I would sell it. 17-40mm is much sharper and optically better, so there's no reason in using the same focal length.

Don't expect to get rich. EVERYBODY and his dog has that lens and I wouldn't be surprised if you find it takes a while to even get rid of it.

Only reason you might want it is if the kit lens is lighter and easier to carry around. I'm not sure on the size or weight of your new lens, so that may be something to consider, and the kit lens is only worth around $100 used.

I would hang on to it. Many cameras come with that lens, so most people with a DSLR wouldn't be needing it., so you wouldn't make much money off of it. Plus, it is probably lighter and might be nice for vacations or something where you don't want a heavier lens. And it's good to have a backup if anything were to happen to the 17-40mm, so you would still be able to use the camera while waiting for a new lens. For the amount of money you would get, it probably isn't worth it, just keep it as a backup.

I'd keep the 18-55.It weighs less than half as much as the 17-40 and focuses much closer.

Unless you're going full frame at some point why buy the 17-40 in the first place? I bought its bigger brother the 16-35f2.8L II for my 500D (T1i) and was so disappointed with it I placed it in the back of my cabinet and forgot about it. A few months later I got the 5DM2 and almost as an afterthought tried it on the full frame. Wow, it came to life! Being a bit of a collector I have 9 lenses and am in the market for a few more. Once you get the 17-40 you may start looking at the 70-200s, then a good macro, a fisheye perhaps, maybe a couple of fast primes but one day you're going to come to the realization, as I did, that the 18-55IS (not the II) is the best value for money zoom in the entire Canon line up. Don't be in a hurry to get rid of it.

I sold mine after buying the 17-40mm. You won't get much for it. Maybe at most $100. I don't see any reason for holding on to it unless you need a lens to take into places you're afraid of damaging your nice lens. The photo quality is horrible by comparison to the 17-40.