I have one overlapping tooth in the top that I would like to fix! Alternative to braces and how long would it take? (photo)

It looks like you are talking about the tooth on the upper right next to the front tooth. Teeth can be changed cosmetically by doing bonding or veneers. Since the gum height is the same as the same tooth on the other side, you would need to smooth your tooth down a bit and place the veneer over the tooth to make it look like it is straight.  You should know that the space for the veneer or bonding is smaller than the same tooth on the other side.  This will make the new tooth appear a bit smaller.Make an appointment with a dentist who does a lot of cosmetic dentistry so you will get a great result!Bonding will take about 45 min.  A veneer will take 2 appointment about 30 min each visit.

One alternative to braces is Invisalign.  Invisalign is a series of removable clear trays that you can wear to slowly correct the rotations of your teeth.  In terms of how long treatment will be, I would consult with a local board certified Orthodontist in your area to get a better idea.  I've included a web reference for more information.  Good luck!