I have to agree with that you should wait at least a day but not more than a few days. You don't want the woman to forget where she met you, and also you don't want to seem too forward.
But most importantly, if you say you will call, CALL! I think one of women's biggest pet peeves is when a man says he'll call and he doesn't.
I'm not familiar with the email address stuff, but I must say, we are almost in the year 2008 so it definitely fits with the "time."