Not that i've seen, you need a certain control gear to make a fluorescent lamp dimmable and usually a certain type of dimmer too. All energy saving lamps I have seen come with standard gear built into the base.
Moonshine, are they truly dimmable, or are they those megaman ones where you dim them by switching them on and off?
or are they those megaman ones where you dim them by switching them on and off? Would you not get RSI in your fingers doing that all evening?
Megaman do a dimmable cfl lamp - but only 11W (60W equiv - why dim that?). It has 4 stages of dimmness - and works as you say by switching on and off - either with your dimmer switch or a normal switch. I've ordered one to test it out at home. They do make them in larger Watts, but not yet available in UK SB
There's http://www.tlc-direct.co.uk/Main_Index/Lighting_Menu_Index/Lamps_and_Tubes_Index/Low_Energy_SwitchDimmable/index.html again switch dimmable but it says "smooth" not discrete steps, and 20W. If you look at the "technical - pdf56k" on the product page, they actually mention a dimmable low energy using a conventional dimmer switch as being "not yet available", so maybe they're working on it??