There is a BugMe for PPC. Dig around on EP's website and you'll find it. I've used it on my x51v... it was "okay" but a little bit (pardon the pun) buggy. I emailed their support and they told me that they planned to release a WM5.0 (and VGA) compatible version sometime soon. In fact, they said "in the next few weeks".. and that was a few weeks ago.
Another program that I have tried is apMemo. It works well and I almost bought it and then I found out BugMe was about to get a new release, so I'm waiting to evaluate it before I make a decision. apMemo can be found here:
http://apsoftsystems.com/apmemo/
apMemo works well.. is VGA compatible and isn't very expensive... so I think BugMe is gonna have a hard time beating them.. but I'm gonna give EP a chance.