Our mini bot deployment works very similarly to others posted on here, surgical tubing to launch the thing out there. Ours however was designed with two things in mind: first, that tolerance was of utmost importance, and second, that having it deploy out the back could cause problems when trying to line up if the towers were surrounded by tubes. At competition, we saw frequently that teams would not be able to align because human players had landed 5 or 6 tubes around the tower and when they tried to back up it just smushed the tube between the bot and the tower.
Here is a video of our in action (at 2:00) and it the same 80/20 bar with sliders but its tensioned forward so you can simply drive up the pole and further and know you will always be lined up:
http://www.youtube.com/watch?v=83OX6P4SSzw