Additionally, Summon a Friend as well as Grant a Level are available from the right click menu on the character portrait.

Summon a Friend appears to be a spell you cast, ~3 second cast time, upon which the target gets the "foo is summoning you to blah, [accept] [cancel]" dialog just like the other summon spells work.

It seems that granting a level gives you however much XP is in your current level, although there is no entry in the log for the XP gain. I had 206 XP in level 2 and granted myself a bump to L3, upon which I still had 206XP.
One more thing - the Grant a Level feature does not work over long range, I needed to summon my alt out to my location before I was able to grant him a level.