On CodeSnipers today, there's a new post looking at two aspects of getting Ruby on Rails to cooperate nicely with PHP, specifically in dealing with sessions and the structure/layout of the files that make up the site.
Not all projects can jump ship from a home grown PHP site to Rails, especially projects where there are exactly 1.3 programmers for the project. I was surprised there wasn't much information on integrating php and rails site (spare me the flame wars). All new development will be done in Rails and old PHP will be written in Rails as time permits. I was exploring some of the ways that this could be possible and what possible problems might arise.
Each of the topics is covered in a paragraph detailing what things look like for either side and a possible solution for cross-communication.