By Richard Dale, contributor

Google (GOOG) should buy Research in Motion (RIMM), makers of Blackberry smart phones. Here’s why:

Everyone who uses a Blackberry loves its physical form factor, especially the keyboard, because the phones are great for email. RIM’s famous security adds to this, and makes enterprises and even governments happy (or unhappy, if they like eavesdropping). People also love BBM (Blackberry Messaging service).

But that’s it. Everyone hates the Blackberry browser, the other apps, the integration, etc. In my opinion — and I’m not alone — RIM is on a slow decline, despite their new tablet and touchscreen phones.

Google is looking to extend its platform to everywhere. Put the two together, and you have a great combination.

Google could get the patent portfolio to allow them to use (or better, out-license) that great keyboard, instead of the crappy one on, say, the Motorola Droid slide-outs. Google could even choose to spin off the hardware altogether to a handset manufacturer (HTC?), to reap the benefits of getting Android onto the platform but avoid competing with their channel.

Google could leverage the intense loyalty of BBM across it’s entire messaging line, adding to Gmail chat, etc. Google could add RIM’s great enterprise security. The BB phones would probably enhance the relationships Google has with the mobile carriers, although I am not sure how important that really is. Google would be able to put Android on the BB platform which would make current BB phone users very, very happy.

That’s it… Any comments?

Richard Dale (@rdale) is a partner with Boston-area VC firm Sigma Partners. He blogs at Venture Cyclist.