Sometimes, in larger PowerShell scripts it is hard to find the corresponding opening or closing bracket or brace. One thing you can do, of course, is to write clean code by aligning opening and closing brackets where possible. Another trick in ISE 3.0 is to place the cursor on a bracket, then choose Edit/Go To Match.
The cursor will automatically move to the corresponding bracket. This command is grayed out if the cursor is currently not on a bracket or the corresponding bracket is missing.