iGoogle and Orkut gets file transfer capabilities through Google Talk
Google Talk desktop client is already capable of sending and receiving files. But this ability was not available through the web based client.
Google has now added this feature to the Google Talk applet accessible from iGoogle and Orkut.
They are working on bringing this feature to Gmail which would make it much more useful.
The feature is compatible with the desktop client so you can now share files with other users who are accessing the service through iGoogle or Orkut.