Well, here's something NOT to do. I live in an apartment too, and I found a little gadget that I figured would work great for rear surrounds, and it's the reason I finally decided to take the plunge into the world of home theatre. You can see it in my sig, it's the Kenwood Wireless RFU-6100. It consists of a transmitter, which is hooked into your amp, and a receiver, which is hooked into the rear speaker(s). It boasts 50 watts of amplification power for each channel, and it relays the sound information by radio frequency. Sounds great in theory, but the RF signal gets interference way too easily, and doesn't output much sound out of the speaker(s). I also get occasional bursts of static out of the speaker when the unit is plugged in. Do yourself a favour and don't even consider this unit for easy rear speaker hookup.
What I did with side surrounds was to line the speaker wire on top of the bottom "bump" of the baseboards. I hammered a small nail roughly every two to three feet into the "bump" of the baseboard, angled so that it keeps the speaker wire in place. You can still see it, yes, but it's completely out of the way, and totally easy to remove if needed.
Good luck!
cheers,
supervij