I thought this would be so easy to find, a simple search for "Backup IE 7 Search Providers" on Google would fetch me the answer. But no sir, I found no such thing! I even did a search on Microsoft and even the Knowledge Base but didn't find what I was looking for. The one page that did help me find the solution has an altogether different title.
Well the good news is that; it is really easy!
Simply backup the following registry key and you're done.
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\SearchScopes
Update: Changed the title of this post to make it easier to find via search engines.