My way of getting pics in that "colour", oldnavy, is to put them into Photoshop, desaturate them completely (so they become black and white, but the colour information is, of course, still there somewhere), play a little with contrasts by pushing the overall levels, and then go to the individual colour levels and lower the blue midtones from 1,00 to 0,90 (the pic becomes a little yellow), then up the red midtones from 1,00 to 1,10. That is all I do.
From all I know about my own Powershot (mine's the A95), though, you can also pre-set that camera to "sepia"-toning and you get this kind of photo right away. Personally I tend to find the in-camera toning devices a bit on the strong side ... I like the effect to be subtler.