The Select panel in the new AutoCAD 2010 Subscription Advantage Pack includes the new Select Similar tool, a top AUGI (Autodesk User Group International) request.
With this tool you can save time selecting multiple objects with similar properties. When you select an object, AutoCAD automatically adds all other objects of the same type and with the same properties, to the selection set. You can specify on which properties to filter using the Select Similar Settings dialog box, which is accessible from the Settings option after launching the Select Similar tool. If only the Layer property is enabled when you select a circle, for example, AutoCAD automatically selects all circles on the same layer as the one you selected. If both the Layer and Linetype properties are enabled, however, AutoCAD only selects the circles on the same layer and with the same linetype as the selected one.
The Select Similar tool enables you to select more than one object and it creates the matching selection set accordingly. For example, if the Layer filter is enabled and you select two circles, each on different layers, AutoCAD selects all the circles on both layers. If, instead, you select a circle and a line, AutoCAD selects all the circles on the same layer as the selected circle and all the lines on the same layer as the selected line.
In addition to general object properties, you can filter selections based on object-specific properties including object style and reference name. Object Style properties apply to text and mtext, leaders and mleaders, dimensions and tolerances as well as tables and multilines. Reference names apply to blocks and externally references files including xrefs and images as well as PDF, DWG, or DGN files.
View demo video (This video doesn't have audio).