How does image_lib perform under heavy usage?

[eluser]KeyStroke[/eluser]
Thanks Derek.

Well my question about the queue was about its concept, not asking for any code.

Also, is there a way to catch memory errors (when a lot of people are uploading at once) and displaying a message to the user instead of that ugly PHP message? I thought I could at least display a meaningful error (like "try again later") instead of letting the application crash.