You used to be able to get the package a Delphi component was installed under from the palette. That functionality doesn't seem to be in the lastest versions, though. How can I find which package a component belongs to under D2007 or D2009?
I don't know of any way to do this through the Delphi IDE. However, you can do a search in your registry for the component name. For instance, to find the package that TBitBtn belongs to, open RegEdit and do a search (on Keys only) for TBitBtn. The entry for TBitBtn has a value called "Package Name". This is the internal name of the package, which is probably still not quite what you are looking for. Copy the "Package Name" value (dclstd100.bpl in my case), and do a search from the top (on Values this time) for that value. Once this entry is found you will see the "friendly" package name in the "Data" column.
Under Component|Install Packages, when you select a package, the Components button shows you which components are installed in that package.