You can keep a unified libariry on a sd card and have any relevant binary available whever you stick your memory card. So the folder structure would be something like
SDROOT (OR EBOOT)
>PigWindowsFolder
>>Binary File
>>Config.xml
>>mapping.xml
>PigMacFolder
>>Binary File
>>Config.xml
>>mapping.xml
>PigUNIXFolder
>>Binary File
>>Config.xml
>>mapping.xml
>Projects folder
>Samplelib
eboot binary (or canoo or gp2x binarry or..)
mapping.xml
config.xml
In config XML for the os specific subfolders you will need to do something like:
<CONFIG>
<ROOTFOLDER value="../projects/>
<SAMPLELIB value="../samplelib"/>
</CONFIG>