I've started 'properly' walking recently, in conjunction with WW so I've been losing weight (8lbs in 4 weeks)
I got myself a pair of reebok easy tone shoes and wear them all the time
sometimes I go to the gym and powerwalk on the treadmill, ie at about 4mph on a gradient
I definitely think that walking has toned my legs and bum up, and I'm noticing myself getting smaller all over. My jeans feel looser on my legs. I don't think I'd notice it so much if I wasn't dieting too, I do have about a stone and a half to shift. The trainers are really helping, I'd recommend them.
I think for walking to have a proper effect you have to really put your back into it, IYKWIM - lean forward slightly, swing your arms, walk fast. I can walk about 4 miles in an hour which works out at 15 minutes a mile which is quite brisk.
I used to run but broke my ankle in May and it still hurts too much when I try to jog, but walking doesn't hurt it at all. Plus it's way easier.