ASIHTTPRequest is an easy to use wrapper around the CFNetwork API that makes some of the more tedious aspects of 
communicating with web servers easier.

It is suitable for when you want to submit data to an existing web form, or don't want to mess around with SOAP or 
XML-RPC.

It provides:

*  Ability for setting up progress delegates (e.g. NSProgressIndicators) to show information about download AND upload 
progress

*  An easy interface for adding POST data to requests

*  The ability to submit files on local drives as part of POST data, analogous to the HTML file input mechanism

*  Basic authentication (username and password) support

*  Integrated Keychain support

*  Based on NSOperation to make queuing requests and background operation easy


ASIHTTPRequest comes as part of a simple application that demonstrates many of the features above, just look at 
AppDelegate.m for good pointers on basic usage, or read the comments in ASIHTTPRequest.h for more detail.

ASIHTTPRequest is partly based on code from Apple's ImageClient code samples, so if it doesn't meet your needs, take a 
look at their CFNetwork examples for more.
ASIHTTPRequest is my first open source Objective-C code. I hope to expand the class and example application further 
(unit tests, maybe even iphone examples...) in the coming months. If you find it helpful, please do get in touch!

See also: 
http://allseeing-i.com/ASIHTTPRequest-CFNetwork-wrapper-for-HTTP-requests