I haven't bothered with Pashua, but PyObjC is fairly easy to get started with and works quite well. The only caveat is that the apps you write using the bridge only run on the same major OS version. i.e. apps writter on 10.3.x will only run on 10.3.x and not 10.2.x. Aside from this, for a lot of quick projects, it makes writting a full cocoa app real fast and easy. An example would be the freeware pyWeather that is available on my site. It was coded in just and hour or two using the PyObjC bridge.