ticketing solutions

[Dan Brian]

What are people using to do authentication ticketing from mp? Nothing 
jumps out of CPAN at me, mostly because what I've seen just makes md5's 
out of username/password/expiration. Any recommendations?

Ideally, I'm looking for a solution that might be usable both inside 
and outside mp, over multiple servers. Something like what the Writing 
Apache Modules book describes. Is anybody using that solution? Is it 
decent?

Thanks,
Dan