Suggestions welcome

Its quite surprising to see that the tool I built, more as a hack, is really picking up traffic. I have already seen about 500 visitors on it in the last 10 days and its growing. Given that it is growing, I want to improve the site. I have quite a few ideas (rss support, twitter support, better UI, mail notifications & so on) but I am undecided on what to take up and what may not be useful for the users. So, I am asking you, the users, to provide inputs on what features/enhancements you would like to see. Drop a comment on this post and I will look into it.