My wife and I are out for business in mid-November and are staying in Ontario, CA. Where would be a good place (fairly close) to extend the trip to the weekend that would be reasonably priced?

An hour east is Palm Springs. Head there and enjoy fall in the desert-- warm days, brisk nights, excellent golf.

i was going to suggest palm springs as well about 1 hour
vegas is about 3 hours away
laguna beach between san diego and la

If you wanted a mountain getaway, Big Bear and Arrowhead are quite close. Most years, mid-November is a little early for much snow but you'd have to check that out closer to the time you'd be there.

To the other extreme, Ontario is not far from the beach cities of Orange County. From Seal Beach on the north end to San Clemente on the south, there are a lot of options from wich you can choose. If you wanted to drive a bit further, there are also a variety of beach choices in Los Angeles and San Diego counties.

Yup, I'd say Palm springs too.

Or maybe wine tasting in Temecula? I have never tasted anything I love there, but it could still be fun.

jzellamn-Where are you coming from and what are your interests? That might determine what you would like better. If you like the beach and don't get to it very often, I would suggest the beach. The weather in November is usually pretty nice but could be variable. Newport Beach, Laguna Beach are about a 45 min to hour drive. If you like golf and the desert, Palm Springs is beautiful in November-one of my favorite times for the desert.
Wine tasting in Temecula could be fun (I live 10 minutes from there) but my vote would be for the beach or Palm Springs.