PDAs / tablets
1999-07 Palm IIIx: my love for mobile computing started here
2002-12 Palm Tungsten T: full color changes everything!
2005-11 Palm T|X: the best PDA, spoiled by poor touchscreen
2007-10 Nokia N800: promising, but unbearably slow for a Palm OS fan

Phones:
1999-12 Nokia 3210: wow, a cellphone!
2003-01 SonyEricsson T68i: a tiny tech marvel
2007-01 Nokia N73: my first true smartphone
2008-12 Nokia E90: a real powerhouse, never again without qwerty keyboard
2009-11 Nokia N900: delivered all promises of N800

With E90 I stopped using two separate devices. Convergence is great!