Opinions on multi-source search

[Iago Toral <itoral igalia com>]

Hi,

I would like to work on adding a new feature to Grilo that I had planned long 
ago and I would like to hear your opinions as to how this should be done (or 
if it shouldn't be done :))

The idea is to provide API to allow users to search content in all sources (or 
maybe a specific subset of sources). The use case is simple: you want media 
content related to something but you are not sure where to get it from.

Example: Say you want to do some work about guadec and you need multimedia content 
for that, you can use Grilo to search for that content but you would have to 
go source by source searching, instead it would be more convenient if you could 
just forget about the source and ask Grilo to search anywhere, and you would 
get videos about guadec from youtube or vimeo, images from flickr, etc... all 
in one go.

Opinions?

Iago