Opinions needed

I'm scripting a light-weight, low volume signup registry for a running club. Folks sign up to volunteer for events and the like. There will generally be a handful of signup registries at any one time. A typical registry will only contain 50 to 100 names. Each registry is only in existence for a month or so. I really don't see the advantage of using a real DB [e.g., mySQL,] for this. Don't need any special searching, etc. Am thinking of using a simple serialized array file for each registry; or, using Pear Cache_lite. Cache_lite has several nice functions I can take advantage of. In spite of its name, it can be configured to be permanent. I'd just go ahead and use Cache_lite; but, I'm always reluctant to use a Pear package for fear it may not be updated for for future php releases, etc. I aways aim to keep maintenance to a minimum. Anyone had experience with Cache_Lite? Anyone have an opinion on the alternatives or maybe another storage approach? Thanks, Al........