Well if you're trying to self assess ability there are scales that are normally used based on the practical skills you have.
The EU uses this scale
http://europass.cedefop.europa.eu/Langu ... entGrid/en
There is a similar version used by US language schools that has a slightly wider range, which I can no longer find.
Griffith University has some self assessment tests online.
http://www.griffith.edu.au/centre/call/ ... /japanese/
http://www.griffith.edu.au/school/lal/j ... frame.html
Essentially "I can read a newspaper" has more meaning than "I am Intermediate" The scales also recognise that you can have strong and weak areas.
How you'd map these scales onto jPod101 is another matter.
Maybe it would be useful if jPod were more explicit in the sort of competency required to make use of a particular set of lessons.
But the lessons mostly build on each other so starting at the beginning while daunting since there is so much material is as good a place as any; you will either review known material or learn new material. win-win.