like thunder said, size only really come into play when you go to output the image in print. 

i don't know how many time i've had to explain resolution to people when they give me a SD card from their camera and want me to send them the images so they can email them to family and friends... it's always "so, do you want them to just look at them on screen? do you want them to be able to print them at a photo lab??"

i've got to the point where i just pull the files and send! Last time, there was a scream from the next office over because when i she opened the image of her kid there was just this huge eye staring at her (due to the resolution) .... oh well.

as to your post, limitations last only as long as hardware limits them... there was a time when you could not save a 20mg file because your hard drive was only 20mgs.

:)
retrocity