For all those users who wanted more storage space for Google’s services, Google has come up with Google Manage Storage.
This facility gives the option to the user to manage his storage needs based on his usage by paying a price to Google. This service might be useful to all those users who need to store heavy files in their Gmail mailbox or other services such as albums in Picasa.
Apart from the above, you could also get additional storage space in picasa by paying a premium depending on your usage. The additional storage space gives the users space upto 250 GB.
Here u can check how much space you are using for all Google Services including Gmail & Picasa at Google Manage Storage.