Displaperture brings back rounded screen corners to Mac OS X 10.5 "Leopard". Choose the corners you want rendered as round, choose their radii, and enjoy CRT nostalgia.
What's new in this version:
New in this version is support for multi-monitor Macs--you can choose to round the corners on all attached displays, or (the default) just the one with the menu bar. Displaperture now works with Expose, too, so you won't lose your nice rounded corners when you activate Expose.