I have this problem too, although it's more the pedestrians than the cyclists. I have tried saying:
- Excuse me
- Excuse me, coming through
- On your left/right
- Coming on your left/right
And one of 3 things happen
- They *barely* move to the side
- They pretend to not hear me and get startled when I pass them
- They move but look at me all offended like I gave them the finger or something...
Any suggestions?