Anyway, here's a look at something I made in design class a few months ago.
I have an off-brand MP3 player I got an an office store for around 40$ (US) a while ago. My room mate bought a little external amplified speaker that was extremely loud. At this point I was also looking at Instructables on making your own Ipod docks. All these things came together into this: a unique, tough, and simple dock for an MP3 player that has big electronically amplified sound, all for under 100$.
I was on a college student budget at the time, so I was very limited in the amount of materials I had. I ended up using 1/8 inch Medium Density Fiberboard (MDF). This became a problem, because MDF isn't a super strong or easy material to work with on a small scale, as it is essentially an extremely dense pressed cardboard. The mitered edges kept shredding, it kept falling apart when I cut it, and it generally annoyed me to no end. I would highly recommend using a hardwood or tough sheet plastic for this build.
I mocked it up in cardboard first, then took templates from the mockup, and marked the templates onto the material, then I cut out all the pieces and mitered them on a fancy chopsaw. The body pieces were glued together with wood glue, and the internal components were held in place with hot glue.
The general idea is this: take apart a BoomCube amplified speaker and stick it in a custom case, with a hole that the MP3 player sits in and the audio jack pops into place. The speaker is mounted underneath the cone. The cone is meant to be reminiscent of an old-fashioned Victrola or record player, but it serves no purpose other than to look interesting and direct the sound. The BoomCube lives up to it's job and blasts the sound quite well.
Here is the link for the BoomCube. They are available online or in the As Seen On TV section of large stores like Walmart.
The dock works off the battery from the BoomCube speaker. In back is the on-off switch, indicator light, and USB charging port. The MP3 player and the BoomCube use the same size of USB port, so only one cable is needed to charge both gizmos, and even sync music to the MP3 player.
If you have any questions or comments, Comment!