These 4 new(ish)XMB PS3 themes are from the official PS3 japanese website, downloaded and packaged for your convinience. New(ish) because the "pink" theme has been borrowed from the PSP. Just unpack the file, save to a memory stick and insert into the PS3, then select themes from the XMB and at the top you will see "install", click and select the memory stick, Enjoy.
For all people having troubles:
Step by Step Guide:
1: Download file off Rapidshare or off the Japanese sony site
2: Get a form of portable media (SD card, Flash drive, USB memory stick)
3: Create a new folder on the memory stick called PS3
4: Then create a new folder inside the PS3 folder called THEMES
+++ If you downloaded from r/share the folders will already be created++
5: Place the theme files that you downloaded inside the THEMES folder
Folder should look like this: Memory stick-->PS3-->THEMES-->"theme file"
6: Insert memory stick into PS3
7: select themes from the XMB
8: At the top select "install"
9: Select the theme to install and click ok
Repeat steps 8 + 9 for each theme.