heh. I saw the "old as your dad" part and had to wonder... as old as your dad, assuming you are how old?
I'm 30, so my dad is a bit older than say the dads of those who are 14-16.
Well, my dad likes chess.  I find Puzzle games like bejeweled, or Zoo Keeper on Nintendo DS are awesome time killers.
My wife's dad is even older than my dad, and I cring at the thought of him even near a computer.  he likes golf and card games apparently.
Personally I try to keep a Palm Zire on me, or my DS, so that I've always got time killers handy.  Zoo Keeper is great, so is Worms for Gameboy Advance/SP.
Oh, and just remembered! 

  For those of us who like the old consoles, they're ressurecting old platforms in those "hook-to-TV" units!  Theres an Atari one thats got a bunch of 2600 roms onboard.  And apparently, the Commedor 64 one is actually a C64 on a chip!  (but minus the OS side, just the game roms)
Even better yet, is to get a Gameboy SP, and one of those writable GBA Rom kits!  I used to have one with 200 NES roms on one cart!