New online service?

[Telos]

Question is a simple one: Do you have an online service in mind that you would like to exist but doesn't exist at the moment? I have a free host/domain waiting and since I already have a personal website I was thinking that maybe I should put up something different. Something that everyone could benefit from. Do you have any ideas what that something could be?

One idea I had is to put up an online tips/reminder database. All those tutorials around the internet of how to do things and no one can remember all of them. So when you read a good tutorial (can be something else too) you can write it to my service with your own account. That way you can collect a personal database of things you like to remember. So whenever you must do something that you read about few months ago you can login to my service and read how it went. This could be usefull already (at least for me) but the point is that those tips and stuff are public information. They are categorized and searchable by everyone.

I don't know if this is a good idea or not. Just something that came to my mind. Give me your opinions and if you have any new ideas I'm open for them.