I find the Google Notifier to be invaluable, since I don’t get a large enough volume of mail to run a native client while at home. A number of months ago, the rate at which it checked for mail decreased significantly.
Luckily, there is a simple fix: defaults write com.google.GmailNotifier AutocheckInterval # (where # is the number of minutes between checks)
Just jotting this down so I don’t lose this. Adapted from the original instructions on MacOS X Hints.
Long overdue update: There was a post here explaining how to mess with your iOS settings to get the Mail application to “archive” instead of “delete”, as some people prefer one behavior over the other.
As of iOS 4.2, this tutorial is completely unnecessary, as there’s a setting to choose whether you want the now-default Archive method, or a regular old delete. You can find it in the main account settings for your Gmail account:
I have nuked the previous tutorial, as it was confusing and useless in light of Apple engineering out a better option.