Grading my event volunteer experiences. How would your nonprofit stack up?

I enjoy volunteering at events. It's a fun way to meet people and get to know an organization. And sometimes it's a free ticket to an event that is beyond my budget. My experiences have ranged from great to, well, pretty frustrating.

Environmental organization tabling at a festival
Signed up for a shift via an event-scheduling website linked to the organization's Facebook page. There was no field for giving my contact info! Two nights before the event, my mother got a message for me on her answering machine from a guy speaking so fast she couldn't understand him. I went over to hear it myself, and after listening to the message five time I was able to make out a volunteer coordinator's phone number. (This guy must have found my mom in the phone book since we have the same last name, but I'm wondering if other relatives got calls too.) Fortunately, the event was great. No followup from the organization though. Grade: C

Nonprofit tech event
Sounded like an exciting, ambitious program. Signed up via an event scheduling website after seeing an announcement on Twitter and got an auto-response thanking me and promising further information. Followed the event updates on Twitter, but I never got any information by Twitter, email or phone about where to go and when. I got a follow-up email thanking me, even though I didn't attend. Grade D-

Family literacy event
Signed up over email. Waited a long time on a dark street corner in a not-great neighborhood to be picked up by staffperson who didn't have much to say to me on the way to the venue. Got almost no info upon arrival. Watched volunteers stick with each other instead of talking to parents or kids. The children's session was chaotic. I never heard from this group later, and I never went back for subsequent events. Grade: F

Human rights organization selling fair trade goods at a festival
Signed up by responding to an announcement in an email newsletter. Quickly got a response thanking me, promising follow-up. Several days before the event I got another email with instructions, directions, a schedule with volunteers' names and numbers, background info on the petition we were asking shoppers to sign, plus contact info for the staff. Had a very good time. Four days later I got a handwritten thank you card and an email inviting me to volunteer again. I'll give this group credit by name: The InterReligious Task Force on Central America. Grade A+

As is often the case, the details matter. As an organizer, I'm more aware than ever how important the follow-up is. What works for you, and what doesn't, when you volunteer?

UPDATE: Three years later, I am still involved with IRTF because they have such a well-run operation. I've recently increased my involvement from occasional tabling to working with the board and staff on boosting their fundraising efforts.