I just came across this handy hint on Google Operating System. You can upload people thumbnails to your Google Contacts from Picasa 3.8. The thumbnails then filter through to other services which use your Google Contacts like Android devices that sync with your Google Account. Very handy.
Picasa 3.8 makes it easier to upload pictures for your Google contacts. After scanning all the photos from your library and adding name tags to your photos, you can go to the Tools menu, select Upload and click on Upload People Thumbnails.
Source: Google Operating System (click for more info on the tip)
What do you think?