Here we go, my first try of doing a walkthrough
Watch the first briefing, we get a webpage and a phrase.
Go to the indicated page www.palminternal.com, there you find a pad with 12 buttons, like a cellphone has 12 buttons. We also get the phrase "iBeforePre". On a cellphone letters are arranged to certain buttons for texting and such things. If we take the pad we see as a cellphone and we "text" the phrase "ibeforepre" the pad lifts and we get to the next step.
I added numbers to the buttons, so the solution would be as follows: 4233673773
After the pad lifted we find a puzzle. Here's a solution to the puzzle (Thanks to dahcheet and macfanrobin)
After solving the puzzle we get to http://www.palminternal.com/root/. Click the button on the very top right corner saying "Upload Files to Mainframe" and we get to the second briefing. With it we receive two pictures.
On the first picture (The one about the museum) it says Bostwicktonville Old Museum of Modern Art. We take the first letter of each word and that leads us to www.bomoma.org.
On this page we find different pictures in the Gallery section, and one picture has a signature in a corner that looks familiar to the scribble in the corner of the black picture from our second briefing.
So we take the black picture, and lay it over the one from the gallery so the two scribbles match and we end up with this picture:
Now we go back to www.bomoma.org to the section "Visit the Museum". In the text there is a link (if you click on any word with a bold first letter) and we get to the page www.bamspart.com. Here we find a map.
The map looks very similar to the picture from the Gallery, so we look at where the white spots from the overlaying picture would lead us to:
University, Rue de Musée and South Point. The different shapes of the white indicators mean different things:
The star on a map usually means where you are at the moment, which is at the Rue de Musée (where the museum is located, so no more clues here).
We find a tree with the white spot at South Point, so we click on South Point on the map at www.bamspart.com. Under Attractions we find Liberation Park, which gives us a clue to the page : www.liberationpark.com.
The other white spot shows us a fish and a telephone, the telephone will be relevant later. If we click on University on the map at www.bamspart.com we find at Restaraunts & Bar the "Franks Flagship Fish Factory", which gives us a clue to the page: www.franksflagshipfishfactory.com.
Let's look at the flagship page first: It looks like a normal page from a restaurant, but what points out are the flags on the top of the page, they look weird, and there's not really a pattern in there that would be decorative to the page.
So we find out that those flags are actually nautical flags representing numbers, we find a translation for the numbers to the flags on wikipedia:
So translated we get the numbers 8 0 1 9 3 8 5 3 0 6. Here's where the telephone next to the white spot comes into play, this is a phone number 801-938-5306. If you call this number there is an answering machine saying the following:
"Agents, what I'm about to tell you is vital to your cause. Seek out Mondrian encrypted ascii, coded vertically, got that? But the key, you better write this down. Do you have a pen? I'll wait.. Alright here's the key: R 1 Y 2 B 4 G 8 W 16 K 32. Take what you find head to the park. Then work all the angles out ok? Don't screw this up."
We find out that Mondrian refers to the Dutch artist Piet Mondrian. Now we got back to the Gallery section at www.bomoma.org and find one picture which is in Piet's style and decode it with the key we received from the message on the answering machine as follows:
R Y B G W K stand for colors : Red Yellow Blue Grey White and Black, so 1 for red, 2 for yellow, 4 for blue, 8 for grey, 16 for white and 32 for black. He told us that it is coded vertically, so we take the value of the colors according to the code and add up vertically.
Then we look at this chart from wikipedia and use it to translate the numbers into letters.
This leaves us with:
1+16+4+16+8+4+16 = 65 = A
1+16+8+16+8+16+1 = 66 = B
16+2+8+32+8+16+1 = 83 = S
4+4+16+32+4+16+8 = 84 = T
4+4+16+32+16+2+8 = 82 = R
2+32+1+16+8+2+4 = 65 = A
2+32+1+4+8+16+4 = 67 = C
16+2+16+1+1+32+16 = 84 = T
8+8+16+4+16+16+1 = 69 = E
16+1+16+16+16+16+1 = 82 = R
16+1+4+4+32+4+4 = 65 = A
The phrase ABSTRACT ERA. The message says that we should take what we find and go to the park.
So now we go to the second link we received from the map which is www.liberationpark.com. Here we go to Historical Society and click onto the picture next to "Unidentified Statue". We end up at http://www.liberationpark.com/limitations/.
We realize that the wings of the statue can be moved if we click on them and drag them around.
There are letters engraved on the base of the statue. What we have to do now is enter the phrase ABSTRACT ERA by using the wings to symbolize each letter according to the semaphore flag signals as shown in this picture:
So now place the wings to positions for the first letter "A". When you're done click one of the letters A on the base and it will light up. Do the same thing with the next letter "B" and continue until you entered the whole phrase.
Once you are done with the whole phrase the base will change into a scroll which you can click on and you will get a PDF-file called overprint.pdf.
(Thanks to macfanrobin for inspiring me to take a screenshot of the scroll)
If we go back now to www.liberationpark.com and click on "Park Map" we can download this map as a PDF file. We realize that the two PDF-files we have now are the exact same size, so if we lay the overprint on top of the map we end up with this:
Now you can either print this out and fold it so the arrows meet in the middle, or you can just cut the middle part out and you end up with this:
This picture shows us the gesture we are looking for to get our precious loot, with a nice little message on the bottom saying "Enjoy your loot".