This is a bit of an unusual build, as it's hard to define as a single object. It uses a Solar-powered battery to power a phone charger, two sets of LEDs and a USB port. But it is very useful and being housed in a book, looks pretty cool too :) It certainly solved my first-world problem of being too far away from wall socket to charge my phone. Total cost for me came to £14 but I had some parts already. If you were starting from scratch, I would estimate about £18 all-in.
You will need:
For all parts:
A Book (small enough to be easily portable, big enough to fit all the gadgetry in)
Helping Hand (see my other instructable #shamelessplug)
Wire cutters/strippers (you can use a small penknife)
Magnets (4 to 6 fairly strong and small ones)
For the Phone charger:
A solar powered phone charger (spend at least £10: anything cheaper will be useless. I used a PowerBee model available on Amazon)
A phone (yeah...)
USB type A PCB mounting socket
For the LED lights:
3 x 3mm superbright white LEDs (about 5000 mcd) (all the electronic components in this Instructable are available in the UK from spiratronics.com)
3 x 3mm superbright colour cycling LEDs (about 5000 mcd)
Either a SPDT or a DPDT slider switch
6 x 47r carbon film resistors
Microswitch (or lever switch) with normally closed contacts
You can make this Instructable without including either the USB socket or the LED array, comment if you're not sure how.
Let's get started!