Taking Mtg Attendance

We’re having a community metting and, instead of having a manual sign-in sheet I’d like to see if there’s an easy way to collect attendance electronically and as easily as possible. Any ideas?

I wouldn’t like to do anything like having folks send an email (many might not both) or maybe even go to a website. I’m thinking more along the lines of having people text their names to some collection point where the information would be stored for the organizers to collect. Is there such a thing (or something similar) as a free service?