This example builds from a branch, but by changing relevant paths, you can build from trunk or whatever branch you want.
From athena account: ssh isdasnap@isda-build1
mkdir build-17jan2008/
cd build-17jan2008/
svn ls svn+ssh://svn.mit.edu/zest/thalia/ui/branches
svn co svn+ssh://svn.mit.edu/zest/thalia/ui/branches/thalia-UI1.0-sprint4
cd thalia-UI1.0-sprint4/
mvn compile
cd ..
svn ls svn+ssh://svn.mit.edu/zest/thalia/ime/Branches
svn co svn+ssh://svn.mit.edu/zest/thalia/ime/Branches/thalia1.0-sprint4
cd thalia1.0-sprint4/
mvn clean package -Denv=test1 -Dincludeui=true -Duipath=/home/isdasnap/build-17jan2008/thalia-UI1.0-sprint4
mvn clean -Denv=test1 -Dincludeui=true -Duipath=/home/isdasnap/build-17jan2008/thalia-UI1.0-sprint4 tomcat:undeploy tomcat:deploy
mvn clean -Denv=test2 -Dincludeui=true -Duipath=/home/isdasnap/build-17jan2008/thalia-UI1.0-sprint4 tomcat:undeploy tomcat:deploy