y'know....
It's not the same as being there, but the WFTDA has a live broadcast stream, as well as an
archive page. The top results when I last loaded the page featured bouts with the Leeds Roller Dolls and the London RollerGirls vs the Central City Rollergirls and the Helsinki RollerDerby, respectively. There might be a bout near you, but there almost certainly is a way to view one near you.
Check it out!