I love my Gmail drive. While I have various ftp storage areas and whatnot, the clean integration of my Gmail account into Windows Exporer as a 1 GB drive is nifty as heck — and useful too. I have put a shortcut on my desktop and there is something darn fine about being able to drop a file on it and have it end up stored on Gmail, ready for retrieval elsewhere. Sure, it’s not shareable space, but it has its uses.
More broadly, this is an example of the sort of open application I am seeing built more and more. The Internet is the operating system, and lightweight apps built on top of open (and not-so-open, in the Gmail case) APIs are one way forward. Sure, this is a small and almost frivolous example, but rest assured it won’t stop here — and it already hasn’t, if you consider the number of developers working on top of Ebay and Amazon’s more formal APIs.