Is huge PHP memory neccessary for big web apps?

[eluser]Ascenti0n[/eluser]
[quote author="depthcharge" date="1243779412"]This is a little off-topic, but i have got to ask where did you get your cool avatar?

Is it something you created yourself or from some kind of online system?

:-)[/quote]

It's an avatar created with my xbox360 profile. I now use it for most of my online IDs associated with my Ascenti0n username.

[eluser]outrage[/eluser]
The only memory problems I have come across happen when creating thumbnails from large images.
Setting the memory limit at 80Mb allows me to process images up to about 1Mb in size.