Thanks guys, that's good advice. Like I said, I have very little experience actually USING design rules, so I'd like my first time to go smoothly. I'll probably try and break my teeth on some standard T20 designs, and then work with some new stuff. I didn't have any concrete ideas, but here's a few random things-
1. Lower tech maneuver drives: let's say I want a rocket based (or other reaction drive) that requires fuel and can regulate the speed based on the speed of the burn. Actually, don't even bother, as I'm never going to play a game with reaction drives. My next idea though...
2. I'm not sure how many of you are familiar with David Weber (I suspect more than a few), but how about his Honorverse impeller drives? You know, the ones that have accelerations in the 100's of g's. (The more modern warships accel at like 550 g's). Slightly different is the Starfire universe which uses a drive field that is inertialess (power to field = movement, no power = dead stop). Those ships can get up to significant fractions of c (but fortunately the "near-c bombardment option" doesn't exist, since their drives must have constant power applied, it just wouldn't be practical, unlike in the Honorverse).
3. Star Trek style warp engines or Star Wars style hyperdrive. There's also the David Weber "sailing through hyperspace" variant and the straight, effectively non-FTL "warp point" system of Starfire. I guess most of the other sci-fi FTL systems are a variant on one of these primary types.
4. Weapons are significantly easier, and with the examples already present, I'm confident I could successfully BS any random weapon technologies that I like. Most of the ones I'd ever use are already there. I might apply my "natural Armor Piercing" idea to shipboard weapons too, but then I'd also be inclined to give ships 1-3 points of "free armor" (GURPS gives a minimum of DR100 to all ships, to protect against micrometeorites and the like).
I guess that's all for now. Also, Mink, when you're done with your stuff, I'd love to see it.