A great tool for Mac OS X is Little Snitch. It’s a tool that monitors all your applications network activity and lets you create rules to allow/disallow certain network activity.
It comes with a small menubar application, Little Snitch Network Monitor, that shows the current network activity. The menubar icon uses red and green bars to show the amount of download and upload. This choice of color conflicts with Mac OS X Leopards system wide use of grayscale menubar icons.
I’ve changed the tiff files used by Little Snitch Network Monitor to grayscale pictures to make it more inline with the rest of my menubar icons. To do this yourself copy the files from the zip-file into /Library/Little Snitch/Little Snitch Network Monitor.app/Contents/Resources.
Hey! Thanks a lot :) I’ve been looking for something like this, the default ones look out of place to me.