With the new Workflow 2.0 in GP, approvers can delegate approval. After all, even though you can approve via email on your phone, that doesn’t mean that you want to when you are on vacation.
Delegation is assigned in GP in User Preferences>Workflow Delegation.
You can delegate all workflow types or specific workflow types and you can set time frames.
I’m not sure how you delegate without a GP account. It appears that you can pick who you are delegating for but I wasn’t able to really test that and I managed to lock up the window a couple of times playing with it, so it’s a bit of a work in process. Still, the functionality is pretty cool.
