For two people, SuperShuttle (which is irritating for a number of reasons) is probably not much savings over a taxi. However, the taxis from IAD are very expensive, too, since Washington Flyer has a monopoly on them. Y

ou can arrange things beforehand with other car services. I can't recommend speciific ones as I use public transit, but I have seen a few people post recommendations in the past.

One public transit option that might make sense is to take the 5A bus to L'Enfant Plaza and take a taxi from there.

As for meeting with locals for drinks, post your travel dates to the DC Happy Hour thread in Community Buzz here and we can probably figure something out.