Check out this new plugin from Marius Silaghi:
Radial Symmetry allows you to model radial structures and see the end result. Situations in which you could use the Radial Symmetry modifier are:
– When modelling anything with a radial structure (eg. rims, tyres, flowers)
– When you what to prototype something circular
– When you want to kit bash something fast
Radial Symmetry is available for Max 9 to 2012 and costs €25.