I haven't seen this possibility discussed on the board before, so I figured I'd post some findings of mine. The following is a recipe for blackhole and antiblackhole (whitehole?) weaponry.
1. Create a freefall bomb.
2. Make it a planet-type weapon
3. Give it a count of 1
4. Give it a single submunition
5. Set the submunition type to the same ID number as the weapon
6. Set the submunition limit to 0
7. Set it to detonate at end
8. Set the blast to be harmless to the player
9. Make it immune to point defense
10. Don't give it any speed, ionizing, mass dmg, energy dmg, recoil, or decay values
11. Set the impact to -32767
12. Set the blast radius to around 200
The above creates a stationary "bomb" which will attract any ships that stray within a 200 pixel radius of it. The ships are basically pinned to the spot. As a bonus, the ships do not become hostile. Changing to impact to a positive value repels the ships. The blackhole (negative impact) is useful in game for attacking fast ships. They can still shoot, but they are pinned to a single spot. The antiblackhole I've found to be more useful. If you have a fairly low reload value, you can string out a line of antiblackholes and create a barrier to other ships. Circling them traps any ships inside the circle, or provides a fortress if you stay inside the circle. I'll be posting a plug-in (Gravitic Weaponry) with these two weapons if anyone wants to examine the coding further. As a sidenote, if you make these yourselves you can tweak a lot of the values, but you must leave the weap as a planet-type weapon, otherwise it will detonate when a ship passes over.
------------------
Pretty much, Apple and Dell are the only ones in this industry making money. They make it by being Wal-Mart. We make it by innovation.
-Steve Jobs