But this is my preferred method of pointing a domain because I like the email forwarding and other features that come with Name Cheap, and it only take a couple of minutes to update the ip should it change. (I only had to update it once so far).
Here is how to set up a domain at Name Cheap using an ip address with a website hosted for free at 50webs.com.
3. Copy the ip address and go to your Name Cheap account, click “Your Domains/Products” in the upper right sidebar on your account page:
3. Next click on your web address:
4.Click All Host Records in the left sidebar:
5. Enter the ip address you got from your 50webs account into the @ and www text boxes, and select A (Address) from the drop down menu:
The @ and www text boxes are to ensure that the domain works both with or without the www in the domain's url. Click the Save button near the bottom of the page and you are done. It will take anywhere from a few minutes to several hours for your domain to begin working.
To set up a domain with dns see the post Pointing Domain To Free Web Host.