I want to know where I can buy an iPod Nano 4GB white model and have
it delivered to me by Friday this week.

Look into these links. These can help u

1. http://www.bizrate.com/buy/noncat_prod_details__oid--350812953.html

2. http://www.ecost.com/ecost/ecmac/search/search.asp?Search=APPLE+White+2GB+iPod+nano&NavID_Search=false&CurDSN=simple&calledfrom=1&incimage=on&submit1.x=19&submit1.y=13

3. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5812566929&category=84084

In google give "iPod Nano 4GB white model" and serach. All the links
for online shopping will be provided.

Also if u want to get thro some shops , those links also will be provided.

Thanks