You do need a Bluetooth or IRda port in order to be able to transfer data to your 3650 phone. The Nokia 92xx Communicator does have the ability to connect to a PC via a serial cable. But no the x650 phones.
It is possible to installl your application if you don't have Bluetooth or IR capability.
Just create an email on your PC, with the ".sis" file as an attachment. You can set up an email box for your phone - talk to your service provider.
Then you just email the file to the phone's address.
The file will appear in the Inbox of the 3650, and you can then choose to install it.
I've done this many times during development. Bluetooth is very nice to have though. It works very well.
Why is information about data cables inconsistent around the web? Even cnet sez that the 6510 has no data cable support or data interface, but i found one selling on another website. What does Nokia say?