Ways to Check Understanding

I have been teaching Internet basics (working with brousers, navigating between sites, Internet search engines).
To check how well the class understand what it is all about, I use:
1. slides summing up what has been said in the covered section of the lesson;
2. practical assignments (“You have 3 minutes. Make site www.sitename.org your home page.”)
3. “quick quiestion tests”: “Does a .com site belong to a govermental or a commercial organisation?”

What other forms to check how well they get it you would recommend?

I thank in advance eveyone who would wish to take part in provididng answers