But a lot of people (like me) wouldn't know how to do that, or even have a USB for that matter.
Well, USB thumb drives are ridiculously inexpensive nowadays (8GB for $14.99 off of Amazon), and it's not that hard to put up a tutorial. Here, you can even use this:
1. In the video replay menu in GT5, press triangle and select "Export Replay as Save Data".
2. Exit GT5, and insert USB thumb drive into a USB port on the PS3.
3. Go to the Save Data Utility on the PS3's XMB menu (the main menu you always use), and copy the exported replay data to the USB thumb drive.
4. After the data has been copied, remove the USB thumb drive from the USB port on the PS3, then insert it into a USB port on your PC or Mac.
5. Copy the ENTIRE replay data folder (Path on the thumb drive should be /PS3/Savedata or something very similar to that) onto your PC.
6. Archive the ENTIRE data folder using a program like Winzip (PC) or the by right-click and selecting "archive selected folder" (Mac).
7. Sign up for an account at
www.mediafire.com, and upload the .zip file you created.