I have been learning Japanese for about 3 years. Here are some resources I have found useful.
I bought a second hand Palm Vx on Ebay (for around £30) to help with my Japanese learning. Two excellent pieces of software are available, one free the other cheap.
A fantastic, free, open-source Japanese learning program. Contains a large English-Japanese-English dictionary, kanji handwriting recognition, large clear fonts, a rudimentary flash card program, and animated kanji stroke order diagrams! PADict Website
Supermemo is a flashcard style learning program with an algorithm that presents cards for review based on the speed at which they are forgotten. With daily use it dramatically reduces the time and effort it takes to learn vocabulary. PalmOS, WinCE and desktop versions are available at a price (PalmOS version costs around £10). The new Supermemo 2.0 supports hi-res fonts.
To use Japanese on the Palm Pilot you will need a way of displaying Japanese fonts. I use CJKOS, but J-OS is also reported to work. Another method is to buy a native Japanese device.
The following vocab lists are in plain text format (Shift-JIS encoded), with tab delimited fields. This is the format used by the PalmOS Supermemo program, but can no doubt be used with other programs. I will add to these lists as I work through the books.
Japanese-English-Japanese vocabulary lists (with Kanji readings) for the text book Japanese for Busy People II.
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10
Chapter 11 Chapter 12 Chapter 13 Chapter 14
Keyword-Kanji lists for James W. Heisig's Remembering The Kanji vol.1.
Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7
Chapter 8 Chapter 9 Chapter 10
Jim Breen's Japanese Page - A huge collection of links.
I'll keep adding to these links as I find new Remembering the Kanji resources.