Gmail is not yet open for general business, but its not actually that difficult to get one. At first I was like some others, and would hang out on the IRC channels and every once in a while would throw out a desperate plea, "I want a Gmail account ..." but to no avail. Still, I wasn't than hung up on it, and so I let it go.
Then, the other day I went to my blogger dashboard, and there stuck in among the other random stats was a gmail invite. (blogger and gmail are both owned by Google.) But unlike some in the blogsphere that are making a big deal over invites, I turned around and sent off three invites to a couple friends who I thought would like them. (Sorry if you wanted one, I'm all out at this point.) I am doing an experiment with another blogger account, just to see when the invite shows up, so if that test pans out I'll have a few more invites. Of course if I was really mercenary, I'd use one of my invites to open another account for myself and then I'd have three more invites. (One wonders how far one could go with that, or why there are 3973 auctions on ebay for these things.)
So, I'd say, if you want a gmail invite, start a weblog, and sooner or later you should get one.