Oddly, unless I’m missing something, there doesn’t seem to be an easy way to upload several pics to Picasa in one easy swoop.
Go to Gallery and display all your pictures.
Click the Share icon.
Brings up Share Via window.
You are now asked to select the items to upload (one or more).
Add a Caption (optional, gets attached to each item).
Select your Picasa account (which should have been previously set up in Accounts and Sync).
Select your Album or create a new one (click the + symbol).
(If creating a new one, I usually find I have to create it twice).
Click on Upload.
It can take a little while to establish the connection and start uploading, but once that is done it continues in the background.
If an upload fails, it tries again after a short interval.
Use the Notifications to see progress.
cick here :https://picasaweb.google.com/lh/settings
third last option is :
Upload photos by email: enable it by checkbox allow me to upload via email
enter secret word
you will see email below this.
copy and add it to gmail contacts as picasa.
now you just have to go to gmail and attach the images and send to this picasa email id to upload.
I hope gmail allows mutliple files to be attached.