signature size checker
 

this checks the size of the images within a users signature. great for forums with restrictions on signature size, only a beta for the moment but its been in almost constant use on my forum for a month or two and thanks to Xenon i've fixed the only bug that came up within that time.

copy sigsize.php into the modcp
create a file 'temp_file.txt' in your forums root; chmod 777
add this to your postbit templates

above:
this works better if your mods have the ability to edit/suspend signatures, but they can always report oversized sigs to admins for editing.

You may also want to look at this hack which actually prevents people from having sig images over the set limits.

that looks to me as if it prevents people having sigs that are visually big. this one is concerned more with file size. We have a limit of 80kb for sigs and mods can suspend them for being over the limit, meny of my mods were complaining that image files sizes were hard to work out so i wrote this to help out. Everyone found it very useful so once i'd got rid of all the bugs i'd found i released it here.

There is an update later in the thread that limits file size as well (called image weight). Yours is a good option too, lets you be more flexible by just alerting mods to it, rather than putting a hard limit. Just thought I'd point you to another option that would save you guys some administrative work, so instead of policing it, checking image sizes, and suspending people, the other hack just makes it impossible for anyone to have a sig image that's too large.