Somebody think about cache?

I seen another weblog product, maybe phpweblog, who use a kind of "cache"... the first user pregenerate the php and save everithing in a cache directory... I think this could help if you have a lot of visits and you don't want to hit the database for every user... think about this: If you use database in you home page, every visitor hit your database... in that case I suggest two things:

• Move all the database content to anoter place
• Put cache o someting like cache

Now I can imagine at least two ways to implement this:

• Regenerate cache automatically every XXX minutes/hours
• Regenerate cache every XXXX hits
Of course, this could be dangerous because your site doesn't refresh everithing, but think about saving CPU, fast resolved pages... if you thing big, you need to handle this. Regards... Fercho.-