On his blog today Court Ewing has posted a tutorial about a different approach to merging strings while formatting them at the same time - using sprintf and printf for more than just a single-shot output.
I do it, you do it, everyone does it! We all concatenate. If you're simply combining a few variables or constants together, concatenation is the way to go. After all, it is quick and easy, and who can complain about that? However, concatenation does have two serious drawbacks: any sort of string formatting must be done manually, and it is difficult to visualize the "goal" string when it is sufficiently complex.
He talks about the benefits of string formatting over basic string concatination like how easy it makes casting variable values - multiple or single - without you having to cast them manually and append. He gives a few code examples of how it can be used for simple formatting and how it can make escaping data used in multiple spots easier. He also includes a SQL query example showing the difference between using sprintf and a normal concatinated statement.