I've been lurking on the site for a while but haven't really posted anything yet...my wife is now at 34 weeks - due at the end of July. We've had a few issues with sleeping, but tried a few things that made a big difference, maybe they will help you too...

1. French style bolster - a long tubular pillow that is about 180cm long that helps her sleep on her side whilst providing support for the chest, bump, knees and ankles - as it's all one thing it's easier to manage that lots of smaller pillows.
2. Earplugs - we both occasionally snore, so we bought some disposable ear-plugs....it's better than lying awake at night or going to sleep on the couch.
3. Diet - She seems to have become much more sensitive to diet as the pregnancy has progressed, keeping dinner simple, digestable and early makes a huge difference to her night's sleep.