Just wondering if anyone has experience with the three. I have used read through some RoR and used Django. They seem fairly easy to use. Is lift \"easy\" like these two are?
I'm currently working on a series of projects in lift, so I'll give my personal experiences.
Its a very capable framework - and I find it makes lighter work of application development than the equivalent in rails or django. However, you will need a reasonable understanding of scala in order to get started on sophisticated app development as documentation is existent but limited, and not centralised.
Lift itself has cherry-picked a lot of features from existent frameworks - rails and django included - to form, imho, a best of breed framework. It also uses some novel techniques of its own that truly mean you can take a frontend and build an application around it relatively quickly.
Following the tutorials, you can create the classic "todo" application demonstrated by many frameworks with little to no experience within 2-3 minutes. But I would say that you need to have a reasonable knowledge of Java, and an understanding of scala in order to get the most out of lift.
Setting up a comfortable development environment isn't exactly painless, due to spotty scala support in the mainstream IDEs.
If you have a weekend you can dedicate to getting started and reading the book I would highly recommend taking the plunge.
As a more direct answer to your question, in terms of "ease", I would say that if you are unfamiliar with Java, scala, ruby and python, then of the three, your best bet would be rails - as ruby is a beautiful language, nigh on self-explanatory, well documented, introduces the majority of OO concepts, and is very easy to learn. Additionally, I know of many people that have actually learned ruby solely through developing in rails.