In the past, we've mentioned several of the retirement planning tools that use Monte Carlo simulation.  Fidelity just unveiled their new tool, myPlan (see previous post) and we've added the T Rowe Price tool to our calculator page. 

Terry Savage explains Monte Carlo and mentions other financial firms that use this technology.

For example, Wachovia  calls its service "Envision" -- certainly a more encouraging process, but one that uses the most sophisticated Monte Carlo modeling tools. Financial advisers on a Morgan Stanley  team call their process a "Retirement Design Blueprint," also a euphemism for Monte Carlo. Vanguard calls its modeling process "time pathing," while Fidelity avoids naming it anything but a "tool" to help you estimate and stay on track.

Only T. Rowe Price, one of the earliest providers, comes right out and says "the analysis we perform to provide you with a recommended retirement strategy relies on sophisticated computer modeling known as a 'Monte Carlo' analysis."