Need help, Comp will be a gift

This is my third build thread that I need help from the community with. First was an i7-920 for myself, next was a P2 X3 720 for a friend, and now I need help with an even cheaper system for my little sister.
My little sister just bought a house and has no computer. I thought a nice little budget build would be a cool house-warming gift from her techie big brother.

APPROXIMATE PURCHASE DATE: In the month of November

BUDGET RANGE: As cheap as possible say, >$600(US) (that $600 will need to include a monitor)

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Very light computing by our standards. Email/Office/Browsing/Flash games

PARTS NOT REQUIRED: I need everything

PREFERRED WEBSITE(S) FOR PARTS: Newegg works, also Ewiz

PARTS PREFERENCES: I gotta believe that an Athlon II X2 will be my best bet. *Maybe* a E5200 but I'd doubt it.

OVERCLOCKING: No
SLI OR CROSSFIRE: No

MONITOR RESOLUTION: I need one, but I'm hoping for a nice 19" at 14x9

ADDITIONAL COMMENTS: Just the basics here folks. Honestly if I can't do this for cheaper than a Dell/HP I might just suck it up and sell-out. I know they can crank out cheap PC's on slim margins.

Something I threw together real quick. Probably room for improvement.

Motherboard: GIGABYTE GA-MA785GMT-UD2H AM3 AMD 785G
$90

CPU: AMD Athlon II X2 240 Regor 2.8GHz
$60

RAM: Mushkin Enhanced Blackline 2GB
$50 (Could swap out for 4gb kit or find cheaper alternative)

PSU: PC Power & Cooling Silencer PPCS370X 370W
$40

HD: Western Digital Caviar Blue WD1600AAJS 160GB
$40

DVD: SAMSUNG Black 22X DVD+R 8X DVD+RW
$31

Case: Antec Three Hundred
$52 (Could find one cheaper or quieter, just threw it in)

Total Before Monitor: ~$360.00

Monitor:
Hanns·G $115
Acer $120

Grand Total: ~$480.00

To reach $600.00 after keyboard and mouse you could upgrade the HDD or put in a 4gb ram kit. The above is a good starting point I hope at least. Also someone should double check for mistakes as I didn't really put all that much effort in.

Silly me forgetting to include an OS.

Shortstuff's looks great. Slightly different from mine with more ram, bigger hard drive, an OS(lol) and the processor I meant to include.