Have you ever tried to use the { and } characters in the c# string.Format() method?  If you have, then you probably ran into a problem.  I'm posting this because this little Gotcha might not turn up until much later if your string formats are dynamically loaded from some external source, such as RESX files.

In any case, I sometimes find it useful to write some JavaScript code directly in C# and then dynamically insert it into the page with the ScriptManager.  Here is a quick example:

Basically, I write my JavaScript code on multiple lines with the @"" notation.  Then, I have to escape all { and } characters using {{ or }} otherwise string.Format will run into a System.FormatException: Input string was not in a correct format exception.  I can customize my JavaScript (or insert control.ClientID parameters) this way while retaining a readable format in the C# code.