I checked "sent a postcard/email/letter/fax." I just moved, and sent an email to one of my state representatives last week, and the other this week, mostly so I'd have their email addresses handy for when there's something I actually want to call about. In both cases, I picked something where I could just say "as a constituent, I support you on what you're doing."

I figure, sooner or later, there's going to be something I'm interested in that my new reps aren't already working on--or where I want them to change their minds--at which point having that info handy will be useful.