Groovy

Classpath in groovy

http://dustinwhitney.blogspot.com/2008/03/groovy-classpath.html

Simple connection to oracle
http://docs.codehaus.org/display/GROOVY/How+can+I+dynamically+add+a+library+to+the+classpath

Here are some books/resources if you're interested in doing some extra reading on Groovy and Grails.
Groovy Books- Groovy in Action (Dierk Konig): A little out of date, but probably the best reference- Groovy Recipies (Scott Davis)- Programming Groovy (Venkat Subramaniam)
Grails Books- DGG v2 (Graeme Rocher, Jeff Brown)- Grails in Action (Glenn Smith, Peter Ledbrook) Manning - not out in book form yet, but you can get the EAP pdf directly from the publisher)
Websites: Groovy Website: http://groovy.codehaus.org/ Some good groovy slides: http://www.slideshare.net/glaforge/groovy-and-grails-in-action-devoxx-2008- university-guillaume-laforge-presentation
Grails website: http://www.grails.org/Grails Reference Guide: http://grails.org/doc/1.1.x/