Phidgets are an easy to use set of building blocks for low cost sensing and control from your PC. Using the Universal Serial Bus (USB) as the basis for all Phidgets, the complexity is managed behind an easy to use and robust Application Programming Interface (API). Applications can be developed quickly in Visual Basic, VBA (Microsoft Access and Excel), LabView, Java, Delphi, C and C++.
[from www.phidgets.com]

1. Download the Phidgets sources (the Phidget Framework for Linux). The filename looks like this: Phidgetlinux_2.1.2.tar.gz
2. Unpack the archive
3. Go into the 'phidget21' folder
4. Edit the Makefile and change the JAVAHOME entry to the destination your Java SDK (not JRE) is located
5. Run 'make'
6. Run 'make jni'
7. Run 'sudo make install'
8. Download the Phidget21.jar file (for the Java JNI platform) and put it to the class path of your Java project
9. Additionally, there's a README file bundled with the sources. Read it.

Finally, perform a 'sudo ls -la /usr/lib/libphidget*'. You should see something like this:

-rw-r--r-- 1 root root 313724 2007-10-31 13:11 /usr/lib/libphidget21.a
-rw-r--r-- 1 root root 362418 2007-10-31 13:11 /usr/lib/libphidget21.so
lrwxrwxrwx 1 root root     20 2007-09-10 15:50 /usr/lib/libphidgets.so.0 -> libphidgets.so.0.0.0
-rw-r--r-- 1 root root  37428 2007-01-12 19:58 /usr/lib/libphidgets.so.0.0.0

Important: you have to run your Java application as root. Otherwise the RFID related things won't work. I'm searching to fix this limitation.

Find more information in the forum at www.phidgets.com/phpBB2/.