(Found via the TFD LJ feed. I know it looks like I am just hitting the feed once and posting whatever comes up. Not the case. Do you know how much crap is posted there? After you get through the barfing dog and two headed cat pictures, there is still all the glitter words and the "I am taking a picture of myself in the mirror." images. Seriously, it can take an hour to find something good. Not to say it's not fun or a nice waste of time. Just didn't want you to think I wasn't working hard for you.)
I have found it helpful to do the stretching exercises my physical therapist recommends. Do some core strengthening exercises, such as the ones highlighted at The Mayo Clinic. By keeping your core strong, your back won't put itself in a position to cause that sciatica pain you are having.