In a quick post to her blog Lorna Mitchell mentions a deprecated method in pecl_http that could cause problems for you down the road - addRawPostData.
I'm a big fan of pecl_http, which I use quite often as I work so regularly with APIs and on systems where I can get it installed, it's much nicer than PHP's curl extension. Recently though I've been often seeing output which reads: Function HttpRequest::addRawPostData() is deprecated
The alternative is to use the "setBody()" method on the HttpRequest object instead. This, in effect, does the same thing and sets the contents of the message to the raw data you'd like to post. Unfortunately, the PHP manual page doesn't reflect that this method is deprecated. You can find out more about the functionality the "pecl_http" extension has to offer here. It's a very flexible and reliable way for your scripts to interact with remote servers via HTTP calls.