Ok - this may sound a bit weird...
There's 3 kids, 2 boys 1 girl - The two boys create a small blue tinted bubble type thing on their computer that they fly around at great speed. At one point smashing through a bookcase and puncturing all the books. They then make the 'bubble' bigger and get inside it then float into the air - using it to look through the bedroom window of a girl from school that they fancy. Then they team up with the girl all get in to 'bubble' and fly into space where they meet two green aliens who have been monitoring advertisements broadcast on terrestrial TV! Please please help before I lose my mind. Ta

That movie is called the explorers. From 1985 it has River Phoenix in it. Check it out at either www.imdb.com or at www.fast-rewind.com

I remember that movie! It was cute! It also starred Ethan Hawke.

That's called "Explorers".