Tuned last.fm autocomplete to do what i need (:

app/controllers/artist_controller.rb

@@ -55,7 +55,7 @@ class ArtistController < ApplicationController
     end
 		render :json => {
 			:query => params[:query],
-			:suggestions => suggestions
+			:suggestions => suggestions.take(10)
 		}
 	end
 	
@@ -63,7 +63,7 @@ class ArtistController < ApplicationController
   	return nil if query.nil? or query.strip.empty?
 		json = ActiveSupport::JSON.decode(open(
 		  'http://www.last.fm/search/autocomplete' <<
-		  '?q=' << URI.escape(query)
+		  '?rows=30&q=' << URI.escape(query)
     ).read)
     return json.empty? ? nil : json
 	end