It is never a FOUL. In the NBA it constitutes a traveling VIOLATION. In NCAA and high school play, there is nothing wrong with doing this. It is legal.
The NBA and NCAA rules are available online, but the NFHS rules are not unless you are a member of the NFHS, and then you can view the casebook.
Here is the NCAA clip, which you can find at:
http://www.ncaa.org/library/rules/20...ball_rules.pdf
BR-89 RULE 4-63/DEFINITIONS
Section 66. Traveling
Art. 1. Traveling occurs when a player holding the ball moves a foot or both feet in any direction in excess of prescribed limits described in this Rule.
A.R. 35. A1 attempts a try at Team As basket after having completed the dribble. The try does not touch the backboard, the ring or the flange or any other player. A1 runs and catches the ball before it strikes the playing court. Is this traveling? RULING: When A1 recovered his or her own try, A1 could either dribble, pass or try again. There is no team control by either team when a try is in flight. However, when the shot clock expires and a try by A1 or a teammate has not struck the ring or the flange, it shall be a violation of the shot-clock rule.
For NFHS (high school) refer to 4.43 Situation B on page 32 of the casebook. It says almost exactly the same thing as the college rule, and it specifically states, "Is this traveling? RULING: No."