The Impossible Astronaut - "All the secrets you seek can be found here on the Webb" (web?)
Day of the Moon - "We found your message your alive but what secrets do you mean my friend"
The Curse of the Black Spot - I mean I glimpsed him and may the gods help him or perhaps you can.
The Doctor's Wife - "To see what I saw click on the spot beyond the Doctors home planet"
And when you do it links to this video (Sorry Moose, you may have to try and see if anybody's got this up on Youtube, dunno if this works outside the UK):
So at whatever point that video's set the Doc knows he's on borrowed time. So the two obvious questions are when is
it set and who is it for? Also, notable that the first three messages sound like they're part of a conversation (or conversations) and this one just tells you how to find a video.
And on Digital Spy where I saw this posted they commented that the name of the video, "Analysis Lessons", is an anagram of "Lonely Assassins", which was what the Doctor called the Angels...