Multiple Spoofed HTTP Requests

Hi list, 
I've used a variety of tools such as Nemesis, Packet Xcalibur & Libnet GUI to 
craft customized packets. Using such tools, you can create packets at layers 2 
up to 5 possibly spoofing your source IP, port numbers or whatever you see fit. 
The question is : Would it be possible to craft a HTTP request(or multiple 
requests) using a spoofed IP address? I'm inclined to consider that it's not, 
the reason being you must have a 3-way handshake established before you can 
start talking application layer protocols (such as HTTP). If you use a spoofed 
IP address, then there's no way of doing that. On the other hand, I might be 
totally wrong, that's why I'm asking the list, for the list is wise. 
If, however, it is possible could you please give me some directions on how to 
do it? 

Thanks a lot
S.

------------------------------------------------------------------------------
Audit your website security with Acunetix Web Vulnerability Scanner: 

Hackers are concentrating their efforts on attacking applications on your 
website. Up to 75% of cyber attacks are launched on shopping carts, forms, 
login pages, dynamic content etc. Firewalls, SSL and locked-down servers are 
futile against web application hacking. Check your website for vulnerabilities 
to SQL injection, Cross site scripting and other web attacks before hackers do! 
Download Trial at:

http://www.securityfocus.com/sponsor/pen-test_050831
-------------------------------------------------------------------------------