If you're stuck in a rut and need to nudge yourself out, you should read this piece and come right out. These are some of the most random things to do with friends, and you'll want to try each one of them.
Embarrass a Friend
All this should be done in jest, mind you. So pick a friend who can take a joke and gets conscious easily. When you're in a public place like a restaurant, go down on your knees, extend your hand and ask them if they'll be your lab partner/shopping buddy/buy you an Xbox―anything random that does not go with the action.
Say it out loud so everyone can hear and say you won't get up till they've agreed to it. Keep repeating the request and ask the waiter to play a romantic song. It's so ridiculous, your friend will probably give in. It's more fun is if you do it to the same-sex friend. If it doesn't work, ask your other friends to join in and nudge him further.
'Harass' a Salesperson
Get into a clothes shop and ask for a cloth size that is either too tight or too loose. When the salesperson starts to give you your correct size, insist that you want the other. When they give in and give you the piece, try it out and then come complaining that it doesn't fit.
Either that or get your friends around to come out and clap when you exit the changing room. One of the most fun things to do with friends, really.
Take up a table in a restaurant and take turns acting out dares. For example, you could ask a friend to open up an umbrella inside the restaurant and sit with it. Ask another to tie one side of her hair in a pig tail, the other in a bun and take a round around the restaurant. You can come up with several things like these.
Stage a Gay Scene
Choose a public place and play a prank on a friend with this prank idea. While he eats at a restaurant, ask another guy friend to come along and profess his undying love for him. The friend is not keyed in on it so it'll be a camera moment to catch his expressions.
Act Like a Nut
Stand on a crowded street and approach anyone, then ask for directions. When they look at you, turn into a cock-eyed person, they'll be completely shocked and won't know how to react.
Or you could even stop them and start stammering when you talk, taking your time with the words. The frustration and the sheer patience, it'll take for them to take the conversation through, and the look on their face, so much worth the embarrassment.
If you're not getting out of the house and need some really fun and random things to do with friends at home, play any of the indoor games that you played in your childhood. Try a scavenger hunt, or a ridiculous hose pipe fight in the backyard, or even a game of hide and seek gets the adrenaline pumping fast. Also, you can come up with a list of your own.