"virgin Atmega328PU" to "chip in ArduinoUNO REV3" with only Arduino?

So go out and get some parts.

Board to work on
Solderless Breadboard 400 Tie Points - dipmicro electronics or
Solderless Breadboard 730 Tie Points - dipmicro electronics (more room to experiment with later)
crystal
16MHz Crystal HC49US - dipmicro electronics
two 22 pF caps
22pF/50V Radial Ceramic Disc Capacitor - dipmicro electronics
two 100nF caps
100nF/50V Radial Ceramic Disc Capacitor - dipmicro electronics
10K resistor
10k Ohm 1/4W Resistor ±1% 103 - dipmicro electronics
some connecting wires
Jumper Wire 12pcs for Solderless Breadboard - dipmicro electronics or
Jumper Male/Male Wire 65pc for Solderless Breadboard - dipmicro electronics (much better deal)

So for like $8 you can have a nice little collection to work with for programming parts or experimenting with.
Add a couple 330 ohm resistors, some LEDs, some push buttons, be on the way!
Buy a couple of sets and some header pins and start your own standalone project.

additional blank part
http://www.dipmicro.com/store/ATMEGA328P-PU

Or, buy a bootloaded part