Dropbox allows you to sync your files online and across your computers and mobile devices automatically. Dropbox announced the Dropbox for Blackberry Beta -- but only for the first 500 users to hit the site and request it.
"Sorry! I just checked, It's "All Full" – it only took a few hours for 500 slots to fill, so the team upped the limit to 1,000 later and that too is gone. The beta works with OS 5.0 only, and allows you to Access your Dropbox on the go, Upload files and sync them to your Dropbox, and Share links to files in your Dropbox."
Keep an eye, the team might again up the limit.
More Info: Dropbox Blackberry