You can disguise your Picasa Identity if you do not want others to know your real Google ID. Your Google username is generally shown in your Picasa Web Album address. Like if your Gmail ID is something like email@example.com then your Picasa Web Albums Address will look like this:
You may not want to show you Picasa ID with others at times while sharing your pictures. Though Picasa lets you select a nickname, your ID will still be shown in the URL as shown above. But you can hide your original Picasa ID. Here’s how you do it.
Login to Picasaweb. Then click on Settings at the top. In the right hand side you’ll see a box that asks for your Gallery URL. There you’ll find a link saying “Want to add a new Google username?”. Clicking on this will take you to a page where you can provide an alternate username for your Picasa albums. Put anything you like which is available(i.e which is not taken by others). If you use a username like “myfriendpicasa”, your Gallery URL for Web Albums will look like this:
This way you’ll able to hide your original Picasa ID from being known to others. What’s more interesting about this is that you can logon to your Gmail account using this username as well. This will be an alternate login id to your Google Profile. But you can add upto a maximum of four usernames. You can make this your primary username for logging in to Gmail if you think it is better than the one you were using previously. Don’t worry it is just for your use. You won’t receive any emails if someone sends a message to this ID (say firstname.lastname@example.org).
So, you can hide your original Picasa identity and still share your pictures without a glitch using this trick. And also create a new username for your Google Account.