The best dot-com parties are usually held Wednesday and Thursday evenings and wrap up early enough that the hangover isn't too brutal the next day. Crashing one is easy if you're properly armed -- a dot-com friend's business card will usually suffice. Or, if you're frightened by the drama of impersonation, you can take the more traditional route by logging on to www.sfgirl.com for a list of the week's festivities, then RSVP-ing to any of the given e-mail addresses. At the parties, there's no exception to the rule: The booze flows endlessly and there's usually enough food available to hold it down. And why not share in the New Economy's wealth? These parties, some more extravagant than others (see next item), are a huge marketing stunt, anyway -- so the more to spread the word the merrier, right?