Edit : Latest update http://www.sandaru1.com/2008/04/04/wordpress-picasa-plugin/

I just updated the picasa widget. Thanks for the comments on the early version. Now, you can select the image size. Then, picasa username field get bit complicated.

If you want to use your whole picasa album you can just type your username. If you want only one album then you can put the album name within brackets(Without spaces). Here is an example : username(album).

If you want to get photos from more than one user, then type all usernames separated by space. You can even use brackets with the usernames.

Click here to download