I also have a Hava box and have used a Slingbox in the past. I like that the Hava can act like a rudimentary DVR recording standard MPEG2 streams on an attached hard disk, or you can stream to the Windows client. It can also act like a source for a Win MCE computer, but I could never get it to set up in Vista due to an unrelated IR receiver problem. The Slingbox has a slightly better picture on low bandwidth connections and because of the remote mode will react much faster than the Hava. But the Hava has an S60 and N8xx client. I had my slingbox on my N95 until I had to factory reset and found the free player was no longer there. I also had it running in Wine, but not well. The Hava only works in Windows as far as PCs go.

I really hope they port the player over to the N900.