There are three things that I usually carry around: psp, phone and ipod. But sometimes also a gps module for my phone. They all need 5V power for charging but they have different connectors. So this project is really simple - I just need different connectors and then I solder them to one power adapter (I haven't succeed with ipod adapter but I will explain it later). For the power adapter I used the USB charger as it was cheap and compact.
Step 1: Connectors
1. USB power adapter VIVANCO (price with discount 10 EUR)
2. SE car charger (10 EUR)
3. ipod USB chord (15 EUR)
4. universal USB to USB mini chord with PSP power connector (10 EUR)
The universal USB chord for PSP was the most universal chord that was available. So I decided to use it. The output of power adapter is 1000mA 5V and it's enough for the phone, ipod and gps but not for psp (original power adapter is 2000mA and 5V). Anyway it will charge but more slowly. Luckily gps is using the same connector as psp.
Step 2: Soldering
Step 3: Universal Power Adapter Is Ready
You can do it with much cheaper if you already have the connectors (3/4 of the budget). I didn't. You can also mod this project and add several connectors or LED-s (I hate LED-s but that's me) or bells and whistles. Do it and let me know.