Are you looking for twiple?
Here are some of the easiest search tips:

1. Ask that person for their tweeter ID or UserName (for example one person's ID is SubiNukta)
2. Open your browser
3. In the address bar type in the ID or UserName i.e.  www.twitter.com/TwitterID (substitute the word 'TwitterID' with the person's real ID they gave you, e.g. twitter.com/SubiNukta)
4. Once you get to their page, click on the button that says, 'follow'. That's all there is to it.

Alternatively,
If you don't them personally and you still want to follow them for updates, you can  guess their I UserNames through the Twitter's profile search engine at twitter.com/invitations/find_on_twitter or private sites like tweepsearch.com

Also, when visiting websites/blogs, you may see the Twitter icon/link displayed on the front page (like the one seen at the top right corner of wavuti.com) in which you can click and follow them back.

More twitter tips? Click on the 'social networks' or 'cool sites & application' labels on the right column of wavuti.com and explore more.

PS: twiple = twitter people (people using twitter) and tweeple = tweet people (people who tweet)