In Ruby you can have closures with a 
Block, a 
Proc or a 
Lambda. They are very similar and have subtle differences.
I've found this article very clear to me: 
Understanding Ruby Blocks, Procs and Lambdas 
In short, for what I understood, 
Blocks cannot have parameters and ( 
http://pastie.org/3107157 ) cannot be stored while 
Procs can like 
Lambdas. 
Blocks cannot execute a return statement, 
Procs can and the calling method will return, 
Lambdas can too and simply return the value to the calling method.
Here are the scope examples 
For me this has been the year of Social Complexity, C# 4.0, some Functional programming and testing, JavaScript, Ajax, Smalltalk and now Ruby.
For the new year I see coming Sinatra, Mac, Linux, Lean-Startup, more Agile Coaching, Mentoring and more management.
Let's see what it comes
See also: 
JavaScript: closure scope  and other ideas