Running in a circle is often a fun and enjoyable trick for guinea pigs as well; a lot of my guinea pigs often choose this trick to default to when they're trying to get my attention and ask for treats. It's a super cute trick no matter how many times they do it.
Plus, if you want to add more of a challenge and make this trick look even more impressive, you can teach your guinea pig to run in circles in both directions. Circling in two different directions in response to two different hand signals or words makes for an even cooler and more impressive trick.
All around, running in a circle on cue is a great trick to teach a guinea pig, especially as a starting trick to build your piggy's confidence and get started with trick training. Watch the tutorial video above for a step by step guide to teaching this trick, or find the written tutorial on the How to Teach a Guinea Pig to Circle page.