The last phone I bought before the N900 was an iPhone 3GS. I owned it for exactly 30 minutes. I only bought it because my telco subsidized it a lot, so I could make a handsome profit immediately selling it off (effectively funding my N900), so yes, I can say I upgraded from iPhone to N900.

The last phone I really used was my beloved E61i. For all the wonders of the browser on the N900, I miss the speed of Opera Mini.