Gotta love a crazy rigger for artillery on demand. Get in with the Red Hot Nukes gang and see if you can't phone in an Ares Heimdall missile strike from 18 klicks out. Sure it costs a pretty penny, but sometimes a body just needs to vape a hardened target or get a real flashy distraction. All in the space of 20-something seconds. Paint up your target and let 'em fly.
Alternately, there's always the spirit marm. Again, bound spirits don't come cheap, but if the mage knows your aura, he can astral to your location at around 1 km/s and tear things up.
Of course, combat is only one dimension of how a contact can help a buddy out, but backup on demand can save your life for sure.