dllRun32 is a free, open source replacement for Rundll32, a standard Windows component that allows users to access functions inside DLLs from shortcuts or the command line. dllRun32 is available from the downloads page.
dllRun32 is able to do things that rundll32 can't (or won't). This is both good and bad. Good, because you're not limited to what Microsoft thinks is "safe" for end users (for example, you can call system libraries with dllRun32). Bad, because you're not limited to what ANYONE thinks is safe (so you can call, for example, SHFormatDrive without anything verifying that you really want to).
I want to point out that dllRun32 wasn't written to be a "hacker tool" (although it obviously can be used as such). I wrote it because I felt a need for it; the uses another person puts it to are out of my hands. Remember, tools can have both legitimate and illegitimate purposes.