Okay, I have a new Sorc and I plan to have Orb as one of her main skills. What other main skill should I use? I don't want to use Meteor. I've tried that build before and I don't care for it. Any other suggestions on builds that involve Orb?
Look for the Orbitaller build by Socialism: Fireball/Frozen Orb, with Static Field to give you a cheap one-point dip into Lightning damage. I'm running one in single-player right now: currently Act 5 Nightmare, level 70. She's a lot of fun to play -- I was running /players8 all the way to NM Diablo, and scaled back to /players5 in Act 5.
I think when most people talk about a Meteorb build it's typically a misnomer. You can pump up Meteor for synergies, but you're mostly using Orb and Fireball, which is a fun enough build. As far as other economical places for you skill points, you'll probably want an element other than cold, so you can also try Charged Bolt which can do some decent damage, or Nova if you're really shy on spare skill points.
Since Orb does not require a heavy skill point investment, it does make sense to invest in another skill. Apart from Fireball you can look at Nova or Hydra. If you go with Nova you can get a build that has "melee" play-style as well as ranged, which is quite fun. Also, you can just go Orb only and shred non-CI's with it while letting the Merc take care of the rest.