I was reading [1], and was lectured on how the sun can be used as telescope and a very potent one, btw. Picture at [2]. Searching, I found the linked article. Quote:

"I anticipate that there will be a host of FOCAL space missions launched in all directions around the Sun, each probe launched in the direction exactly opposite to the star to explore with respect to the Sun position…. A FOCAL space mission could be used to magnify anything of interest outside the Solar System. One should then say that FOCAL will be used to magnify the nearby planetary systems, meaning not just the nearby stars themselves, but also their planets, halo disks, Oort clouds, etc."

According to some comments in the article (specially andy's, very informative), one could see another stars' Mercury! Very impressive. And since all EM range is focused, one can use the focal point for radio communication, ala NASA space network[3]. Some catches though: we need to send a probe to 550AU. That would take almost 200 years. Talk about planning ahead :).

[1]http://edge.org/response-detail/26774 [2]http://www.centauri-dreams.org/?p=22321 [3]http://io9.gizmodo.com/5714777/the-suns-gravity-could-be-use...