One of those PDA's should have enough horse power to emulate
a gameboy right? And someone could make a small adapter ( say
for the Visor as an example ) that would fit gameboy cartridges
right? Multitude of handheld games available for your pda
and legally too because your buying the physical cartridges.
Heck using cheap and slow memory they could even put rather
large games on these cartridges. Too large to fit in the pda's
memory itself. Its own form of copy protection. Or has this
been done already. Personally I think the new gameboy is a joke.

Also the VMS's (VMU's) that were born in the wake of the tamagotchi's
to carry small bits of games from the consoles with you seem
to have died a withering death. But slightly larger more
robust versions of these 'mini-games' to build your character
or even just get your RPG buzz while on the train seem like
they could have a place on your PDA. With a small link
cable from your PSX2 to your PDA you could download the
code and keep your characters strengths up. Or just down
load your saves to trade with friends.

I've come to the horrifying realization that colocation at a
decent price doesn't exist.