I've just compared the oAuth process between LatitudeWidget and ZapLoc (which works).

With ZapLoc, I get two pages:

page 1:

The site <number>.apps.googleusercontent.com is requesting access to your Google Latitude account. If you are granting <number>.apps.googleusercontent.com access for the first time, you'll need to grant access to Latitude below and then to your Google Account on a following page.

Do you want to grant <number>.apps.googleusercontent.com access to:

* View and update your best-available location
* View and update your current location

page 2:

The Zap's Location Updater application on your computer is requesting access to your Google Account for the product(s) listed below.

Google Latitude

With LatitudeWidget, I just get the 2nd page:

The LatitudeUpdater application on your computer is requesting access to your Google Account for the product(s) listed below.

Google Latitude

When I look at ZapLoc permissions:

This site currently has access to:

View and update your best-available location
View and update your current location

With LatitudeWidget:

You haven't given <number>.apps.googleusercontent.com any permission to access your Latitude location information.

Hope this helps. Thanks.