I ended up writing a piece of standalone Java code that, based on the ticker symbol as input, produces a comma delimited list of earning dates.
It does scrape Earnings.com site.
If anyone's interested, I can provide the jar. Free of charge of course
Just to provide an update (since I found this thread on a search and others may likewise find it), the Yahoo Finance earnings calendar http://biz.yahoo.com/research/earncal/today.html provides ticker, date, and time. Estimates are only provided for future ERs. And, although it looks like they only go back a few months back (no link is provided to go earlier), you can actually access earlier ERs by modifying the date directly in the URL. I've been able to access the ER calendar all the way back to late 1999.
The data is provided by CCBN, which is part of Thomson Reuters, so it should be solid.