Posted by BeeWolf
you have to have a blackberry account with you carrier. but i just opened one, and pretended I already had a blackberry phone.
then I installed the .sis Blackberry connect file on my M600i, (latest one is 3.37 at secentral.net) as well as the "Blackberry Connect Desktop for Sony Ericsson" (latest is 2.1.1.12) on my PC (also available at secentral.net).
There is also a nice official SE instruction book about all this available at matrixcentro.com site (http://www.matrixcentro.com/micro/blackberry/se_600i.php)
but they don't have the latest BBC and desktop files.
I'm using the BES service, so I also made that live with my company's exchange server. (and connected my t-mobile blackberry account with that email adress).