Well i found mine looking through random fansites.
iconator.com
(link moved), you can find literally tons of Facebook Icons on there.
on facebook. if u already have 1 then look 4 peices of flair.
You can find GaiaOnline twilight layouts by searching on websites that specialize in GaiaOnline layouts and themes. Some examples are GaiaProfiles and Gaiasheet. Look for user-generated content or forums where members share and exchange custom layouts.
You can find some on deviantart
You can find a variety of icons for AIM available online from website such as Iconator. Iconator holds a library of over 1000 downloadable icons for the instant messaging platform.
A buddy icon,a small graphic that, if properly chosen, represents a user's alter ego. These icons can be found at websites such as Cool Buddy, Find an Icon or Quick Buddy Icons.
On LiveJournal, you can find community icons by visiting the specific community's main page. Look for the "Userpics" section, which typically displays the icons available for that community. Additionally, you can explore the community's posts, as users often use different icons in their comments and entries. If you're a member of the community, you may also have the option to upload or customize your own icons.
Information on editing icons can be found on a variety of computer and technology websites. Websites such as CNET, Microsoft, and Apple will have the information needed to edit icons.
Aside from manually deleting the shortcuts and icons on your desktop (the Recycle Bin cannot be deleted): you can right-click the background, find "Arrange Icons By" and press "Show Desktop Icons". This'll hide all the existing icons, so if you press "Show Desktop Icons again, they'll all return.
One can find free RSS icons from the following sources: Feed Icons, RSS Icons (animated), Glossy RSS Icon, RSS Dock Icon, Mycircles RSS, RSS With Reflection, Feed Icons2, Acid RSS, Ojiggo RSS, Grudge Style RSS Icon.
The website Find Icons contains a broad range of icons depicting telephones. The "Office" section of Microsoft's website also enables you to search their set of images. These include icons of telephones. This site also offers filters for size and media type so that you can specify the icon you are looking for.