Update, 24 June 2014: I'm planning to add support for building projects with Cargo shortly. I'll announce it here and on Twitter when it's ready.
Update, 12 July 2014: Highly experimental Cargo support is now available.
Update, 17 September 2014: This post is obsolete. Please see Deploying Rust to Heroku, with example code for Iron.
If you have git and the Heroku toolbelt on your system, this
should be easy:
git clone https://github.com/emk/heroku-rust-hello.git
cd heroku-rust-hello
heroku create --buildpack https://github.com/emk/heroku-buildpack-rust.git
git push heroku master
If you want to create your own Rust web server from scratch, keep reading. But fair warning: Rust is not yet ready for serious web development.