SHOCKERSPAZ  a newer version is available that Allen graciously recompiled to work with the Intel Macs!!!

Thank you Allen!

http://arpspyx.googlecode.com/files/ArpSpyX-1.2.zip  
(Version 1.1)

SHOCKERSPAZ  it doesn't seem to work on my intel mac (a shame really, i love this little app and frequently choose my macbook pro over my windows laptop just for this app).   
(Version 1.1)

ALLEN PORTER  I apologize, the initial 1.1 release was compiled incorrectly and how now has been fixed.  
(Version 1.1)

ANONYMOUS  Version 1.1 seems broken ( well... it IS broken :)

Linking to object files in fixed paths can´t be good :P

ZeroLink: could not load .o file: /Users/allen/Projects/ArpSpyX/build/ArpSpyX.build/ArpSpyX.build/Objects-normal/ppc/main.ob

ZeroLink: could not load .o file: /Users/allen/Projects/ArpSpyX/build/ArpSpyX.build/ArpSpyX.build/Objects-normal/ppc/ArpController.ob

ZeroLink: could not load .o file: /Users/allen/Projects/ArpSpyX/build/ArpSpyX.build/ArpSpyX.build/Objects-normal/ppc/ArpSniffer.ob

ZeroLink: could not load .o file: /Users/allen/Projects/ArpSpyX/build/ArpSpyX.build/ArpSpyX.build/Objects-normal/ppc/NetworkInfo.ob

ZeroLink: could not load .o file: /Users/allen/Projects/ArpSpyX/build/ArpSpyX.build/ArpSpyX.build/Objects-normal/ppc/libpcap.ab

ZeroLink: unknown symbol '_main'  
(Version 1.1)

SILLIUM  Nice application and for free. I'd like to have the possibility to sort by IP- or MAC-Address but thank you very much anyway...  
(Version 1.0)

ANONYMOUS  Good utility when troubleshooting the network around the house. If the thought of running this app in root mode (thereby allowing a program you downloaded off of MacUpdate with the word "Spy" in the title to do whatever it wants on your computer), you can just allow read permission to /dev/bpf0 by typing "sudo chmod 744 /dev/bpf*" in terminal. you may reset it to the original by "sudo chmod 700 /dev/bpf*" or it will reset it's self once you restart your computer.  
(Version 1.0)

ALLEN PORTER  Excellent idea. I will add this option in the next release! Thanks for your feedback.

-allen  
(Version 1.0)

ANONYMOUS  needs to be run as root or gives error message -

use following command

sudo "path to application/ArpSpyX/Contents/Macos/ArpSpyX" check case

developper might want to allow admin acces via password in the gui

otherwise, works well but could send frames to request ARP broadcasts instead of just waiting for them which may take some time to locate all machines on the network  
(Version 1.0)