I checked the documentation and I could not find a way to create a Mac App, it's that possible?
we can just build with phonegap mobile apps? not desktop apps? it's an another framework who do that?
http://docs.phonegap.com/en/3.0.0/guide_cli_index.md.html
UPDATE: As of Cordova version 6.0, Mac OSX platform support has been added.
No phonegap cannot be used to build desktop apps. One of the main reasons devs use phonegap is to allow them to build web apps with the capability to interact with the phone hardware. This gives them ability to write same web app built for different platforms (android, ios, windows phone etc).
Link below provides a list of target platforms that it supports
http://docs.phonegap.com/en/edge/cordova_device_device.md.html
Update : Google around and found : http://fluidapp.com/ (not free but cheap to buy) or https://macgapproject.github.io/ .. never tried either of those
Update 2: Since 2016, PhoneGap/Cordova supports building apps for Mac. For more details, see brianfit's response on the bottom