I have used the Schneider momentary switches for quite a while now (previously with X10, will be reusing them with ST). The best place to get them that I’ve found is here:
That’s a screwless polished chrome retractive switch (with black insert). I’ve gone for these as they matched the existing electrical outlets, although they really do show up fingerprints so brushed might be better if you’re trying to avoid that.
The price seems like it’s at least a few quid cheaper than anywhere else, and they seem to have almost any combination of finishes and inserts that you could want
I have also used Schneider’s modular system ‘Ultimate Grid’:
Plus 2x: http://www.rbstarelectrical.co.uk/products/gug102rbms
This has replaced my hallway light with two retractive switches. I have one dimmer micro module in the backbox downstairs and one upstairs (with a single retractive switch for the upstairs light only). The wiring running between the floors allows me to control the upstairs light from downstairs and upstairs (as originally intended) including full dimming control from both floors.
Additionally, for a fiver(ish) less, these people do Schneider retractive switches with the screws showing:
I hope that helps some people.