Two tools that I really like are PowerGUI, a tool to take all the hard work out of PowerShell scripting, available in both free and paid versions from Quest Software. You can also get PowerGUI extensions for Visual Studio for free from CodePlex.
Another tool I really like is PowerWF. PowerWF is a really cool visual workflow builder that creates PowerShell scripts for you. Turns out that it integrates with PowerGUI!
This video shows 2 different ways that PowerWF Workflows can be run from within Quest Software’s PowerGUI tool.