It seems while you were searching for a way to get back to Sanctuary, the citizens have found plenty for you to do. Collect all of the side quests so we have an immediate list of stuff to work with.
Before we head out in to the field there are a couple of quests that need to be handled here in the city.
The first and foremost: it’s Claptrap’s birthday! Find the annoying, yet beloved robot hanging out in his little trash heap home. The little robot bugger is pretty excited for his party.
You’ll need to invite some people first and Claptrap will hand you the invitations. The mini-map will mark the individuals you need to hand the invitations to.
He invited Moxxi, Marcus and Scooter to the party and, understandably, no one can make it to the shindig.
Return to Claptrap where he has already set up some pizzas and a boombox. As soon as you return and turn the boombox on the party starts. As guests fail to show up things become increasingly awkward.
Claptrap attempts to dance, offers you pizza, even requesting you blow into a party favor to liven things up a bit. When the poor robot realizes no one is coming he immediately shuts down the party.
He offers you pizza and a reward for being such a good sport.
Item: random pistol or assault rifle