Rails 3 plugin development - recommended practices?

I have been thinking that there must be some better ways of doing Rails plugin development than my current approach. currently I tend to have my plugin in one location as a gem and then link to it from my Rails 3 app vendor plugins folder with a symlink. Then I have to carry around the whole Rails 3 app as baggage for development. What is the better option?

Aren't there some libraries, tools out there specifically to meet this need? Seems like various plugin developers each have their own setup for doing this!?

I tend to use RSpec 2 for all my testing needs. How does rspec-rails fit into this?