been searching far and wide for the solution to this and at long last a plugin that finally fits the bill.
As a predominantly 'mobile orientated' community site I was losing around a 50% ratio of new sign-ups as my users were trying to register through their blackberry handsets, and many of them did not have their email accounts synced.
Problem over, installed the plugin, registered a test account on-line, then crunch time, would it stand up by trying to login from a smart-phone, hell yeah it does, I'm one happy bunny !!
p.s. it even logs me in straight to where I need my new members directed to..the activity wall ;)
highly recommended to similar project owners.