Thanks to everyone for the comments.
@Carlo : Yes, you are right. My way of dealing with the URL was rather basic and certainly not bugproof. I have now improved the code with URLBuild:
ImgPlay2[x_?StringQ] := Module[{a, a2, b},
Sow[x, "name"];
a = Import[
URLBuild[{"http://images.google.com/search"}, {"q" -> x}],
"Images"];
If[Length[a] > 0, a2 = RandomChoice[a],
a2 = First@
Import["http://images.google.com/search?q=mickey+mouse",
"Images"]]; Sow[a2, "Image"];
b = CommonName@ImageIdentify[a2, SpecificityGoal -> "High"]; b]
@ Arnoud : From the list of entities you obtain, applying the ImgPlay function, and using ImageCollage, I get this picture of your office (I'm sure you can recognize it :-) ):
