Jacques Marneweck points out a tutorial he came across showing how to perform an installation of the PEAR library system on a shared host.

This is quite useful when you are forced into using a clueless shared host who only have the bare PEAR installation on their servers, and have not ever considered installing DB, Mail, Net_SMTP, etc. which lots of people use instead of reinventing the wheel with each project.

The steps of the tutorial are pretty simple and they include two different ways - installing it to your docroot directory if the web host already has the pear binary set up or using ftp/ftps/sftp to upload and install the needed files.

In a new post to the JSLabs blog today, Justin Silverton mentions a FTP server that's been created entirely in PHP - nanoFTP.

nanoFTPd is an ftp daemon written in php. as of version 4.2.0, php supports the command-line interface (stable since 4.3.0), which nanoFTPd relies on. nanoFTPd is modular, so it’s easy to add custom modules and other stuff, like different database interfaces (currently supports mysql and postgresql).

Features of the app include user authentication via a database or text file, dynamic IP support, and most of the usual FTP goodies you're used to in a server. You'll need at least PHP 4.2.0 to get it up and running, but configuration is simple and installations it just as easy. You can grab the software from their website.