I've been using MAMP on my macbook for doing my web development at home and can't say enough good things about it. Unfortunately I had to start using some binaries not included with MAMP, ImageMagick for example.

Installing ImageMagick via MacPorts is simple enough:

sudo port install ImageMagick

but trying to run it via the MAMP stack gives you the apache error:

dyld: Symbol not found: __cg_jpeg_resync_to_restart
  Referenced from: /System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/ImageIO.framework/Versions/A/ImageIO
  Expected in: /Applications/MAMP/Library/lib/libjpeg.62.dylib

or something similar. I was able to get it to go, but you need to break the sandbox, so it may not be a viable solution for everyone.

Once ImageMagick is installed, head to:

/Applications/MAMP/Library/bin/envvars

Here we want to comment out the two lines:

#DYLD_LIBRARY_PATH="/Applications/MAMP/Library/lib:$DYLD_LIBRARY_PATH"
#export DYLD_LIBRARY_PATH

and add the line:

export PATH="$PATH:/opt/local/bin"

What we're doing is using our systems default DYLD Library path, not the sandboxed one, and exporting our MacPorts bin directory into the sandbox PATH, so it can execute your ImageMagick bins like convert without specifying the full path to it.

Presto! I'm not sure of the full consequences of doing this but I haven't run into any problems yet and nothing seems to break as a result. Always backup the original files tho!