Mattias hasn't said anything yet, so I will...
We just added a component manager to Lazarus. It manages the customidecomps.pas file for you automatically. I just updated from CVS and it's in the current version.
This will make it much easier to add in downloaded components. Look for "configure custom components" in the components menu. Make sure you copy the sourcecode for the components you are adding somewhere in the lazarus units path first. It lets you choose the source file to add and then lists the type definitions available in that file, for you to select what components to install. Once added, you can also configure what page they appear on.
No doubt my parsing on the source files will turn out wrong for someone... so don't be surprised if it does an endless loop or some other sillyness. ;-)
Tony Maro
http://tony.maro.net/
Check out my software "CheckBook Tracker"
A GPL (free) replacement for Microsoft Money!