Smart Folders that are built into OS X will find just about any file meeting any criteria you want and save it to a folder.
To use open a new Finder window and select File > New Smart Folder.
In the resulting window click the plus sign then select "Other" from the first drop-down menu (the default selection is "Kind). There is about 150 different criteria you can select from.
Finder will immediately begin searching your Mac for any files that match the description. When you are ready to save your smart folder, select the "Save" button from the top right of the Finder window. You will then be asked to specify a save name and location and there is a check box to also put a copy in the Finder side bar..