Make Google Notifier check more often? – The macosxhints Forums
If you click on the mail icon, then hold down command and option keys while clicking on preferences in the drop down box, you will be prompted with a box that has a key and value prompt. Type “AutocheckInterval” under key (this seems to be case-sensitive) and then under value type in the number in minutes of how often you want it checked. You will need to quit out of the notifier (again found in the drop down box under the mail icon) and then run the app again for your change to take effect.
This totally works and is great for users of the Mac version of the Google Notifier app. I set mine to something a little less frequent than every minute but the default (15 minutes) was annoying when I knew I was supposed to have an email from someone I was talking to via another means.