Like the other poster said you could go for a remote control setup. 3
dimmer switches from TLC at about £17 each and any spare remote
control you can find. Connect a single dimmer to each light and
programme each one with a different button on the remote.
The dimmers are pretty responsive and work even when pointing the
remote away from the switch so don't let line of sight worry you.
You may even be able to get a 3 gang remote dimmer, (I'm pretty sure
you can get a 2 gang) which would mean you only need 1 switch plate on
the wall.