30 days after i can recreate but will lose all followers and people i follow. the thing i care about most is the 500 folks i followed, a nice group of folks that will be hard to reassemble.
Look into all of the bs Twitter apps that are out there on the internet. When I google my name, I see lots of random twitter apps I've never heard of that keep track of parts of my twitter account--tweets I've retweeted, who's starred which of my tweets, etc. I bet some of them keep track of who you follow as well.
Actually, I doubt it will take you all that long. At one point, I was following ~1,900 people; I unfollowed all of them to get back to the essence of things… since then, I’ve climbed back to 600, and I don’t believe it took me more than, hm… a few months? If you’re trying to re-amass such a following, instead of trying to keep it down (as I was), you shouldn’t have any trouble at all :D
You could also try google cache. http://webcache.googleusercontent.com/search?q=cache:McZbpn8... has 20 of the people you follow(ed). You might be able to get some more if you can find the caches of the followers pages