jwmann-8:twitter[master] $ irb -r twitter.rb
>> james = User.new("jwmann")
NoMethodError: undefined method `keys' for nil:NilClass
	from /Library/Ruby/Gems/1.8/gems/mongoid-2.0.0.beta.19/lib/mongoid/document.rb:117:in `inspect'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:302:in `output_value'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:151:in `eval_input'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:263:in `signal_status'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:147:in `eval_input'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:146:in `eval_input'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:70:in `start'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:69:in `catch'
	from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/irb.rb:69:in `start'
	from /usr/bin/irb:13
>>