Ask HN: What are the Pros vs. Cons of MySQL Stored Procedures/Functions?

I have seen a lot of online discussion for and against the use of stored procedures in MySQL and other SQL languages. Some programmers I know seem to really like stored procedures and functions while others do not. Personally I have never had to use a stored procedure in any of my web apps, but I'm wondering if I am perhaps missing out on something. Do you use stored procedures in your database applications? Or do you avoid them? I'm looking for an objective analysis of the pros and cons.