Your plugin is great! Thanks for developing it. I tried it some time ago and the new version is perfect with the nofollow, new window, etc. Very good job.
Currently using it for a website with a lot of links and it works perfectly. I would also like to link my Twitter username but words with special characters don't get linked:
follow us on Twitter, @VentureWars, https://twitter.com/#!/VentureWars
I've had a look at the code (v2.7.4) to try to make it for you but the RegEx is way too complex for my skills. Any chance you can implement it?