It's not architecturally sound, but teams at all levels build their offensive lines from the outside in, making offensive tackle a very important position.
Since most high school teams put their most talented offensive lineman at tackle, it is naturally the deepest O-line position to recruit. However, many prospects at offensive tackle will eventually be moved to center or guard once they enter college if they lack overall athleticism or ideal height.
The prospects that stay at either left offensive tackle or right offensive tackle are likely to be at least 6-foot-5, 275 pounds when they enter college and have the frame to add weight and the athleticism to maintain their speed and footwork.
The left offensive tackle must be the best athlete on the offensive line. He usually lines up on the weak side with no help from the tight end and is blocking the defense's best pass rusher, who is usually smaller and quicker. Not to mention he also must protect the quarterback's blind side.
He should also be an adequate run blocker, but most left offensive tackles are more finesse- and position-type players rather than overpowering-type players. These guys have the feet and range to "ride" the defensive end past the pocket and also the power to anchor against the run and handle a power or bull rush.
The right offensive tackle is usually a little more physical because he is more involved in the run game. Most teams are right-handed and tend to run to that side. He doesn't have to be quite as gifted as a pass protector, because in many cases he has a tight end lined up next to him.
People often incorrectly assume that the right tackle must be a big, physical guy and therefore doesn't necessarily have to have great feet and quickness. Since tight ends can go in motion or switch to the other side, the right tackle can be put on an island protecting the outside. He still needs to have strength and size because the defensive end that he is playing over is a little more physical than the other side.
Division I-A programs are always going to have interest in any prospect who has experience at both left and right tackle, and tight end prospects often turn out to be excellent tackles with great athleticism, feet and range.