I don't own the Uglies series, Scott Westerfeld does.
The next place that Jimmy went was the future, using his time traveling skills. He went to a time when all of the sky scrapers of present day were in ruins and there were new cities where everybody looked perfect. He saw that in most of these cities, there were always huge parties which looked like a lot of fun. Jimmy wanted to be included in the fun so he made himself age to 16 so he could fit in and went to a city with a huge river near it.
At one of the parties he found that all of the people were really stupid, as if their brain had been altered. After looking over their brains with his X-Ray vision, Jimmy found that their brains had been messed with and would therefore not be any fun.
Since he was displeased with this time period, he cured all of the peoples' brain issues, leaving the world in mass chaos, then went to some other point in time.
a/n Yay, more destruction is left in his wake. Review if you feel like it.