Developer website: Grey Matters
The free version will teach and train you how to remember both long ordered lists and numbers (very handy for remembering PINs, account numbers, SSNs and more)! The basics of all the techniques are just one click of the "Help" button away.
If you already are familiar with memory techniques, you can still use this software to challenge and train your memory. You can even customize the phonetic alphabet (a technique for making numbers easy to visualize) to your particular needs.
A trained memory is a valuable asset in business, in school, or in life. A trained memory is a tool you will take with you wherever you go, and help you stand out in a positive way!