There's a live stream here.
I was looking for a stream on and off for the past couple hours. Eventually had to take a break and have some breakfast. I finally found the stream linked above, which supposedly started at 10:30. So I don't know how long it's been going. Will add more links once it's over as I find them.
Here's a post from the Ohio State University Lantern:
Obama rally to inspire voters, cause parking problems
I need to to get ready for a class now, but will check back in a bit. If anyone has any links to coverage of today's rally at OSU, please pass them along in the comments.
Update: Any Ohioan can vote early by going to your local Board of Elections. This page lists all of the BoE locations.