Does your dog jump?

I've had a foster dog at home for a couple of months, and she's as cute as can be. She is cuddly, smart, and crazy energetic. When she first arrived, she'd been in boarding for months after a scary stay at a shelter - she was pulled by the rescue hours before being killed - and she didn't know anything. I mean, anything.  She tried to jump up on the kitchen counters. She wanted to stand on the tables. She tried taking food out of the other dog's mouths. She'd probably never seen a toy before, and hoarded everything together in a pile that she guarded.

All these things were pretty easy to break, and within a few days, she knew how to sit, knew the word stay means not to go out the front door, learned to go to her crate on command, and to move over when hogging too much of the sofa. She's so good with the crate she runs to it if I go through the room saying, "I've gotta go to work."

Anyway, she has a couple of annoying habits I haven't been able to break yet. She's terrified of leaving the house. When she first arrived, she was afraid to leave my side in the back yard - she probably knows all too well what it's like to be abandoned - but that disappeared within a few days. She likes to go for a ride in the car, if I lift her in. Try to go for a walk... Forget it. We've tried a few steps more every day, but as soon as the house is out of sight, complete panic ensues. I've tried every trick I can think of except one - I will try to put out a trail of dog food, and hopefully she won't notice we're going further and further away. (Not an optimal mode of training, I know. If you have a better idea, please comment on this post and let me know.)

She also jumps a lot of people, especially on me, and it has been driving me crazy. My own dog training skills weren't enough to break the bad habit, and I Googled to see if anyone had some good advice. I didn't know that dogs jump to show submission. I thought they were just overly energetic and happy... That explains why raising your voice to make them stay down doesn't work; they sense they're doing something wrong, and want to become even more submissive, so they'll just jump more.

The website suggested turning your back to the dog that jumps. Tyeah, that didn't have any effect at all.  It also suggested "turning into a tree" every time the jumping begins. I stand absolutely still and stare into the wall. That makes jumping boring pretty quickly. She still does it, but stops as soon as I begin my tree invitation. As soon as she stops jumping I praise her for being such a good girl and staying down.

Other ideas? Have you had the same problem, and if so, what did you do?