Regarding optical mice: it is NOT impossible to rocket jump with an optical mouse. In fact, now that I've mastered it, I find it laughable that I had a problem with the mouse's movements before. Yes, if you move the mouse too quickly, the optical sensor is unable to cope. However, this problem is remedied quite simply: slow down your mouse speed.

It's best to get some practice outside of FPS games. Try practicing on your desktop: from the center of the screen, move the mouse pointer down as quickly as you can to the 6:00 position. It takes a little bit of practice to get a feel for how fast you have to move the mouse in order to get the desired movement. Too quickly, and you'll get the jerky movement described above.

Once you have mastered the timing of going down and staying at the 6:00 position, try the return. Rocket Jumping is useless if you're looking at your feet throughout the span of the jump.

Rocket jumping is useful in all gameplay types, not just Rocket Arena. A successfully timed rocket jump does between 40-45 points of splash damage to your character. With armor, the armor will absorb 30 points, and 15 are taken from health. For game types such as CTF, the Rocket Jump is a valuable tool, even with self-damage on. In Rocket Arena's default mode, where only Armor is damaged by one's own weaponry, expect to lose between 28-33 armor per rocket jump.

When you rocket jump with any types of self damage turned on, you MUST take into consideration how much health you will have left. In modes like Rocket Arena, where players by default cannot damage their health, if you Rocket Jump until you have no armor left, you'll die to one rail fire, or one direct rocket hit. Don't rocket jump, unless absolutely necessary, when your combined armor + health total is 100 or less! Once all your armor is gone, rocket jump across the entire map, but beware, in games where armor self-damage is on, players will know that you're low on health/armor, and they'll try to finish you off using the lightning gun or the plasma rifle.

There is a script that allows players to rocket jump by pressing one button. This script is certified to work with Quake 2, but may not work in Quake 3. Place the following lines in your autoexec.cfg file in the baseq2/baseq3 directory. You may wish to take out the echo statement, but make sure to replace (key)!

alias +rj "rj1;rj2"
alias rj1 "set cl_pitchspeed- $cl_pitchspeed;cl_pitchspeed 100000;wait;+lookdown;wait;-lookdown;set cl_pitchspeed $cl_pitchspeed-"
alias rj2 "set hand- $hand;hand 2;+moveup;+attack;echo Rocket Jump"
alias -rj "-attack;-moveup;set hand $hand-;centerview"

bind (key) "+rj"

This script is supposed to work in Quake 3, but your mileage may vary. I find it has the annoying side-effect of switching the view to look at the ceiling if the fov isn't parallel to the horizon.

cl_pitchspeed 5000
set rjump "+lookdown;wait;wait;+attack;+moveup;wait;wait;-
attack;-moveup;-lookdown;wait;wait;wait;centerview"
bind (key) vstr rjump