There is a neat site called Monitter that allows you to watch up to Three different Twitter HashTag conversations as they happen.

The service is really simple to use and you don’t need to login to watch.

Go to their site and you will see three of the most popular current hashtags on Twitter.

If you want to watch another conversation you can put in anything you want.

Try putting in your own user name or that of someone famous that you like. If you exclude the @ sign you will get more info and see posts from the person and the ones targeted at them.

So if you are interested in a popular hash tag try using http://monitter.com/