xterm is slow while scrolling, yet Terminal.app is quite quick. Why not use Terminal.app instead of xterm? To do this, use this command in a variant of csh.
setenv DISPLAY :0.0(if you don't use a variant of csh, you will need to know how to set environment variables in your shell.)
Put this in your shell init script (which is most likely .cshrc for those who haven't changed their default shell or made a .tcshrc file instead) or just use it at the command prompt. From then on, you can use Terminal.app to open your x windows apps.
This is only useful if you're using XDarwin in rootless mode; it looks great with OroborOSX!

