How often should you check themes/plugins you use on all your sites? daily? weekly? monthly?

what if you are on vacation?

I want a plugin to notify me via e-mail (that e-mail address goes to my Blackberry) when there is an update. If it's a small update, I wouldn't go to a internet cafe and update it (when on vacation) but if it's a big one then yes.

Vacation/Travelling for work/conferences/etc...