I don't know how he did it but he did.
After the cell phone-in-pocket-in-pool incident I let the phone dry out and gave it to Gusi to play with. He played a bit but then gave me this look like, lady you aren't fooling me. And so it sat at the bottom of the diaper bag for several days.
Now that PapaGus has gotten a new, fancy, shmancy phone with FM radio and MP3 player (which means I inherit his old iPod since my first generation one kicked the bucket a few weeks ago), I have warned him to not let Gusi play with it. There are toys and there are grown up things which are (expensive and) not for children. Gusi must learn this lesson. We work hard for the things we have and thus we need to take care of them.
So, that meant that when PapaGus was using (ok, playing with) his new phone and Gusi wanted it, we went to the old pool phone to keep him entertained for a few minutes while PapaGus hid his new phone. Well, at one point we saw Gusi fixated on the buttons like he hadn't been in a long time and then heard the music play as the phone came on. Gusi had been holding down the on/off button and brought the phone back to life! It wasn't turning water into wine, but it was incredible nonetheless.
After the shock wore off and we examined the phone we agreed that it was in working order. But we didn't need this phone anymore so Gusi ended up with a nice used cell phone of his very own. He continued to play as we got ready for the day. Then I heard PapaGus call from the bathroom to come get the phone. Huh? Come get the phone. But before I could reach the bathroom a very wet phone came flying out from behind the shower curtain. Apparently Gusi wanted to show his Papa how his new phone was water proof and threw it into the bath tub. The lights flickered a bit and then went away. We're letting it dry out again and perhaps after a few days we'll let Gusi try to work his magic a second time.