There are many LED bulb instructables that are based on
1. the capacitive droppers : dangerous as there is no isolation from mains the inrush current fries most LEDs
2. difficult to get components also lengthy work to solder many components

Here we do it in a easy way

The LED bulb is a simple LED sec with 2 or 3 Nos of 0.5watt LEDs no no more soldering garden of leds .

We eliminate the component buying with a cheapo 5V phone USB charger . The arrangement is simple as follows

Cell USB charger ---> CCS(Constant current source )---- > LEDs in parallel

The CCS takes care of efficient usage of the LED at peak brightness.

Step 1: Get the Components

you need

1 - 1k resistor
1- bc548 or any NPN small transistor
2-1N4148diodes
1- 10E resistor
1 or 3 Nos of .5 watt high bright LEDs

any 900mA 5v usb phone charger
here in INDIA these are 1$ or less

some verroboard solder etc

Step 2: Make the Ccs

Make the CCS on the board
I have used this

http://www.scienceprog.com/building-simple-constant-current-power-led-driver/

one with

R2=10ohm for one LED , Use 2 ohm for three LEDS
R1=1k and rest all same

Supply the CCS with the 5V from the charger.I think there are many diagrams that tell how to get 5v from charger
refer http://www.mytempfiles.info/hdkeychain/USB_Special_Cable_11.gif
for usb socket A pins to get the 5V .

Place the charger dismantled circuit + the LED ccs board in a slim plastic box
Use double sided TAPE to fix to wall

use a 2 terminal blocks to connect mains wires to the obvious MAINS pins of the charger circuit

The CCS circuit has the ability to give max brightness with the max possible light from the LEDs .

yey! you have made a handy LED BULB that concumes <2watt and enough for corner positions of a mini room
No shock ... no hassle .... save lot of $$ on bills .