Revit can do its own material takeoffs, but if you are looking for a more robust program for estimating (and other tasks) you can try these programs:
Name: Innovaya Product Suite
Author: Innovaya, LLC
Compatibility: Revit 2008, Revit 2009 (through API)
URL:
http://www.innovaya.com/Description: Cost Estimating, Scheduling, Bidding/Quotes, and Construction Simulation.
Name: Building Explorer
Author: Building Explorer, Inc.
Compatibility: Revit 2008, Revit 2009 (through API)
URL:
http://www.buildingexplorer.com/Description: Cost Estimating, Scheduling, Bidding/Quotes, and Construction Simulation.
Name: Vico Product Suite
Author: Vico Software, Inc.
Compatibility: Revit 2008, Revit 2009 (plans for an API)
URL:
http://www.vicosoftware.com/Description: Cost Estimating, Scheduling, Bidding/Quotes, and Construction Simulation.
Name: BSD Product Suite
Author: Building Systems Design, Inc.
Compatibility: Revit 2008, Revit 2009 (planned bi-directional support)
URL:
http://www.bsdsoftlink.com/Description: General Cost Estimating, Spec Writing, and Performance Planning (no labor/material takeoffs).
Name: CostX
Author: Exactal International
Compatibility: Revit 2008, Revit 2009 (through DWF or ODBC)
URL:
http://www.exactal.com/Description: Cost Estimating.
Name: US COST Product Suite
Author: US COST
Compatibility: Revit 2008, Revit 2009 (through ODBC)
URL:
http://www.uscost.com/Description: Cost Estimating. Uses RSMeans.
Name: Sage Timberline
Author: Sage Software
Compatibility: Revit 2008, Revit 2009 (through innovaya)
URL:
http://www.sagecre.com/Description: Project Management Applications.
Name: DesignEst Pro
Author: WinEstimator, Inc.
Compatibility: Revit 2008 (through API)
URL:
http://www.winest.com/products/add-ons/Pages/designest_pro.aspxDescription: Budgeting and Cost Estimating. Uses RSMeans (optional).
Name: QuickBill3D Composer (not yet released)
Author: eBusiness Software 121 Limited
Compatibility: Revit 2008, Revit 2009
URL:
http://www.ebusiness-software-121.com/Description: Cost Estimating.