Hi Mark,
personally I would not mention any certification "in progress" on my CV. Instead I would mention your current "project" during an interview. Why?
1. What does "in progress" mean? Did you buy the voucher? Did you download the assignment? Did you start your implementation? Anybody can do this...
2. I am german and I work in Germany, and my feeling is, that most employers don't know very much about the different certifications, so your SCJP says you are certified on Java, and a SCJD "in progress" needs some explanations, to be an useful information (again: interview).
But of course it is your decision, so if you want to put it on your CV, you can write something like this:
Sun Certified Programmer for the Java 2 Platform 1.x
Sun Certified Developer for the Java 2 Platform (in Arbeit)
Maybe there are better wordings, but thats the first thing that comes into my mind.
Hope that helps,
Jan
P.S.: If you need a good online dictionary try
LEO English-German Dictionary.