KeepandShare provides a powerful search command to help you find the usernames for your friends and add them to your Friends List. Click on the gray "Visit" tab and then click on the "Find Username " button:

You will then see the following screen:

Type text into any of the three fields and then click on "Search Now" - TIP: type a few characters of both their first name and last name. You don't have to type in their full name, if you type just a few letters KeepandShare will find all names beginning with those letters.

Here is a sample of matching names:

You can then click to either add the user as a friend, visit their share page, or return and adjust your search.