FYI Here is the running t5 app: http://ping-service.appspot.com/
It uses T5.0.18 + Spring 3.0.0M4/JPA + Google Datastore/Mail/Cron/URLFetch/Google Accounts Security Works pretty well. I had to implement some hacks to develope with t5 on local dev server (t5 error page refuse to work properly there by default, but works ok in appengine cloud), here is the solution: http://dmitrygusev.blogspot.com/2009/08/turn-java-security-manager-off-in.html -- Dmitry Gusev AnjLab Team http://anjlab.com
