This is a step by step explanation of how to build a 5x5 LED cube using an arduino. I did this project for my undergraduate electronics class and it took me about 2 weeks to complete.
Note: Apparently, some of the links for the supplies and code aren't working, if you need them send me an email at firstname.lastname@example.org.
You can find a video of the working LED cube on youtube here:
And here's another:
Step 1: Supplies
-30x 150 Ohm resistors
-5x 3-8 Line Decoders
-5 NPN Transistors
The manufacturer numbers and prices can be found in the attached document though the cost was about $40.
Additional required materials:
-Sturdy wire (for structure of cube)
-sockets (for decoders)