Scheduled Tasks, caching, widget

[winstone]

Hello,

I've created my own weather widget using Yahoo Weather RSS Feed, it's working fine however I'm wondering on how to cache the content and refresh it lets say every 5 minutes

I figured the best way to achieve that is by using the built-in Scheduled Tasks function but I can't figure out how to cache the content or better say where to cache it, save it in just a writable xml file or store it in databse and retrieve the data from database in my widget

what would be the best way to go for caching and retrieving the data in the widget while maintaining least possible load on server and best performance?

Appreciate your input