You guys do realize those letters are hoaxes, right? You all seem to be taking them seriously.
I can't find much on the Internet about the first one, but the Letter of Lentulus (not Lentrelus, as the often-plagarized-in-full-on-crappy-angelfire-websites article linked to above states) is not only a hoax, but a bad one at that.
From
newadvent.org.
The third letter, from the "Archko Volume" was debunked by one Edgar J. Goodspeed, in his
'Modern Apocrypha, Famous "Biblical" Hoaxes'. A summary can be found
here. (He also debunked the Lentulus letter, summary
here.)
Basically, according to Goodspeed, the Archko Volume (or Archko Library) was a hoax invented by a certain W.D.Mahan in 1884. Your standard "guy invents a bunch of crazy stories for reasons unknown" sort of thing.
Anyway, the first one in which Pilate supposedly describes Jesus to Tiberius Caesar is much more obscure than the other two, but it seems silly to me to think that a local apointee to a backwater of the Empire would write a letter to the Emperor regarding the physical appearance of some itinerant preacher. Also, the part where he describes Jesus as "... leaning against a tree, calmly addressing the multitude," seems suspect. Jewish teachers usually sat down to teach, and the Bible records Jesus as doing the same.
As a side-note, I must say that this was a rather creepy subject to look into on the Internet -- every second website I found was some white supremacist trying to reconcile his Judeo-Christian faith with his ignorant hatred for all things Jewish. It was like wading hip-deep through raw sewage. Repulsive.