Counting WAP connections

I work in a library that has a wireless access point for the public to connect to the internet. We use a Linksys WRT54GC, unsecured and completely open, so users do not have to log in. We need to collect statistics on how many connections are made to the WAP, but this model doesn’t have the logging capability to do this. Is there a workaround for this, or possibly a separate product that can log and save these statistics?