Perfect Scan has been on the Windows Phone Marketplace since late June and the developers have been quit busy with the updates. We've seen an increase in email size (bumped to 20mb) and support for Dropbox and Google Documents.
The most recent updates have fixed bugs and glitches associated with email export and Dropbox crashes for non-US regional settings.
Sending a scanned document to either source is easy. Just swipe over to the DropBox or Google Doc page in the Export Menu, enter your email/password and done. We liked Perfect Scan (here's our review) and adding Dropbox and Google Docs options to the export menu only improves things.
There is a trial version available for Perfect Scan to let you try before buying and the full version is running $2.99. You can find Perfect Scan here (opens Zune) at the Marketplace.