I don't know much about Oracle, but many people have asked about Ruby's support for Oracle. One of my clients is also attempting a project with Rails and Oracle. Here are some useful resources I've found:

Streamlined is a framework that sits about Ruby on Rails and makes developing Rails applications even quicker than possible with scaffolding alone. It includes a ton of useful stuff like pre-built layouts, a REST layer around all the models, support for Atom, and its own DSL. As developer Justin Gehtland explains:

Chris Williams looks at David Heinemeier Hansson's keynote speech at last weekend's RailsConf in Chicago and examines what David has to say about Rails 1.2 (scroll down half a page when you get there).

Cobra vs Mongoose is a Ruby library by Paul Battley that makes it easy to convert between XML and Ruby hashes (in both directions). It's a good alternative to YAML or JSON. It's available as a gem with gem install -r cobravsmongoose. Here's some demonstration code:

Slingshot is just one of many hosting companies getting on the Rails bandwagon. Unlike many, though, Slingshot was launched specifically with Rails in mind, as the tagline says: "When we couldn't find a reliable Rails host, we created our own." If you use the service and have any comments or a review, do post in comments here.

I know.. PHP. Don't stone me just yet! Eric Rollins presents some interesting work relating to generating PHP code with Ruby.

Railsbench, by Stefan Kaes, is a collection of scripts that makes benchmarking a Rails application quick and easy. Rather than benchmark over HTTP, Railsbench tests the 'raw' speed of your application directly, and won't include latencies involved with the network or between your HTTP daemon and Rails. If you love statistics, you'll love Railsbench. Here's some demonstration output:

The Robot Co-op, the team behind 43things, has released several great Ruby libraries for free, all available as gems. Here are some of the highlights:

AD.D SoftWare have developed a new plugin for Rails called cssForm that lets you create forms without tables, entirely using CSS.