You don't need a webcam to view someone else’s webcam. But first you have to make sure that your friend is broadcasting their webcam.

Then, you have a couple ways to view it:

in the IM Window

Click Contact in the IM window, select "Contact Options" and "View Webcam."

in the Chat Window

Select the individual from the Chat List. Click Contacts in the Chat window, select "Contact Options" and "View Webcam."

Note: You can no longer request to view an individual's webcam from your Messenger List.