HLIPPELT  I have been using this program for the last 2 years and it has worked flawlessly. I have been part of the beta for version 5 and have to say it is great. I have had 1 or 2 problems in the beginning (2 years ago with a watchguard), but that was solved on the mailing list. I cannot understand the bad ratings below. The documentation is fine for me and i haven't had any problems.

Interface is really nice now. I have tried other clients, but none was this easy and worked "out of the box".

Price is a bit high though...  
(Version 5.0)

HLIPPELT  I have tried several ways to connect my K800i with O2. Yes i know you can use PAN or some modem scripts or even the connection manager from o2 (which doesn't seem to work for 10.4.9), but this is definitly the simplest way to do it. It just works flawless. Install and connect is all you need to do. The price is a bit high, but if you consider the time you need to get the other soltions working its well worth it.

Great software...  
(Version 1.6.4)