This was a letter sent to my Cleveland PO box right about the time I was moving across the country - so it languished a bit until I had access to a scanner.

Contents: one photo, one small red ticket marked '478'.

Delivery contents:

Letter front
Ticket front
Photo front (photo of a photo, note the lighting blobs)
Photo back

sjwk 07/15/2008

Comments: On the photo back, Walgreens is clearly the name of the shop that
printed the photo.  Could the (13) be the store number?  If so, store 13 is in
Puerto Rico - 35 Calle Juan C Borbon Ste 77, Guaynabo, PR 00969 to be precise
(according to their website anyway).

The photo itself is of the construction of the Golden Gate Bridge.  Not sure
what the boat is, but I found a copy of the picture here:
http://www.sfmuseum.com/treasure/detail.aspx?ID=187

The '478' ticket obviously refers to the 478th anniversary (and associated
meeting) which took place on the 25th June - the day the letter was posted.
Given that it was posted in Las Vegas, did the meeting take place there?

Comments: I'm pretty sure that's the building of the golden gate bridge in the
background, it's an odd angle though.  If so, then the ship  might be the
Thayer, a logging ship that's now on display at the Maritime historical park.

I'm pretty sure the 13 is the number of the store, I'll do some digging and
see if that's the case.

(later)
The 13 is in fact the store number, and it's located in Puerto Rico.
The address is 35 Calle Juan C Borbon Ste 77,Guaynabo, PR 00969

There are many remailing services in Las Vegas. That is the best
explanation of why so many of these are posted from there.	

This could apply and more than likely is a double or even treble reference, since they enjoy that sort of thing: 
The flick Hannibal (2001) has the evil protagonist or at least the protagonist using a mailing service from Las Vegas. 
It's like buried in the middle of the movie and not many people remember it. Starling remarks something to the effect 
that it must have come from a Vegas mailing service when she get's Hannibal's letter.  She gives a reason for this which 
one suspects amused the freaks.  What does Mr. Hance think? Do you agree with Starling's analysis regarding the mailing 
service?

It's interesting that you note the lighting blobs in the photo - this seems to indicate that the photo is of a photo which 
is under glass.  Perhaps someone knows of the location of the original ship photo?  The lighting reflections suggest a 
library, museum, or historical archive.