Ah, now there's a place that just reeks of epicness.
How about the Puente Hills Mall? Bring a banana and a spare flux capacitor.
Seriously though, what are you looking for? The Whittier Narrows Rec area, the Pia Pico monument, the San Gabriel river and Whittier College could all provide some interesting backdrops. Not sure I'd be up for shooting say a wedding at any of those, but they could all be interesting.
I'm going to be doing high school senior portraits. I like using natural light outdoors. Anything interesting with some character that could be used for vintage, urban, rural, etc.
Yeah, so take a ride over to the Rec Area and scout it out. There should be plenty of spots out there. Be better if you can do the shoot off hours like during the week as weekends will find you with several of your closest friends in the backgrounds.
If you can make it into downtown that might be even more interesting. The Music Center/ Disney Hall on a quiet Sunday morning can be pretty sweet.
Go to old town Whittier (I think Greenleaf Blvd?). You could also shoot big panarama shots of Pomona from the hills if you drive up Turnbull Canyon Rd to the top.
I WOULD share some pics BUT, I went to old town to shoot, set up the tripod and camera, then realized mem cards were at home ARG!!
Hardly a spot in Whittier that isn't good. Whittier college is has beautiful old buildings and greenery, you're in old town so from there you'll see many other great urban locations. As also already mentioned, you're about 20 minutes from where Back to the Future was filmed, but the Puente Hills Mall leaves little to be desired as far as beauty (or shopping). You are not too far from Fullerton Arboretum, another great spot. Hope this helps!