I've finally figure out how to fully compile the Mac application from http://gabuku.com/scope/.
The arduino pde compiles & load OK on my mega board.
Using Xcode on my iMac running under Tiger runs OK now but some manipulation is need to store Macduinoscope special file under Xcode hierarchy folders.
Bad news: it launches but then it abort saying
[Session started at 2010-04-23 18:24:24 +0200.]
Macduinoscope has exited due to signal 10 (SIGBUS).
Maybe it is because it is because I use Mega board & pde is made for duamilanove 