Zur Deutschen Version
Feel free to send corrections of my translation! :-)
You'll find the Bookcrossing Helpers Extension (BCH) for Firefox here:
http://bc.ardik.net/bch/bch.xpi
Note: Due to the recent switch to BookCrossing 2.0 this Firefox Add-On is currently disabled!
Eventually there'll be a comprehensive documentation. Until then please have a look at this forum thread:
Announcing BCH.

Bookmarklets:

Firefox users! I recommend the Add on mentioned above rather than the bookmarklets. It's more comfortable and more powerful!

Bookmarklets are little pieces of Javascript code which you can store like bookmarks / favourites. When you activate them they perform some action on the page that is currently displayed in your browser. The changes happen in your browser window only and thus are not permanent. Note! Some of these Bookmarklets currently aren't functional due to the BookCrossing 2.0 launch!
But those which are marked with „BC 2.0“ should work!

  1. BC 2.0 a) Display only books in your possession on your shelf.
    Hides all books that already travelled on.
  2. BC 2.0 a) Display only books in possession of Shelf owner.
    Hides all books that already travelled on.
    BC 2.0 b) Display only books not in posssession of Shelf owner.

    Hides all books that still are in possession of shelf owner.
  3. Display only books registered by user.
    Shows only book registered either by shelf owner or registered by you.
  4. Compact shelf listing:
    Displays only lines with title and author.
  5. Convert BX time to your local time.
All bookmarklets can be combined!

Before installing and using the bookmarklets read instructions below!

BC 2.0 1. Display only books in your possession on your own shelf

This bookmarklet hides all books that already left your shelf.
Usage: When viewing your shelf click on this bookmarklet and all books that already left your shelf will be hidden. Click again and the whole shelf is visible again.
There's slightly modified behaviour with travelling books: When viewing "All Books" the books that the shelf owner set to "travelling" are hidden, too. Of course. But in the "Traveling" view the books that you yourself set to "travelling" will be shown!

BC 2.0 2.a) Display only books in possession of Shelf owner

This bookmarklet hides all books that already left the shelf you're currently viewing (indicated by the words "(set by".
Usage: When viewing someone's shelf (such a list with - currently - up to 50 books) click on this bookmarklet and all books that already left the shelf will be hidden. Click again and the whole shelf is visible again.
There's slightly modified behaviour with travelling books: When viewing "All Books" the books that the shelf owner set to "traveling" are hidden, too. Of course. But in the "Traveling" view the books that the shelf owner set to "traveling" will be shown!
A minor issue: When viewing someone else's shelf the books in your possession won't be hidden, neither.

BC 2.0 ? 2.b) Display only books NOT in possession of Shelf owner

Just the opposite of the first bookmarklet: Hides all books of the shelf owner. I.e. all books that didn't get a jounal entry from another user since they've been on the shelf owner's shelf.
What for? If you use it on your on traveling books list (sorted by Recently Released) which of the book you've once had in your posession were recentyl released by someone. This closes the gap that you don't receive information about release notes by mail...
And used together with "RegBy" (see below) you can easily see, where "your" books currently are...

Both bookmarklets, 2a) und 2b), used together, of course will show you an empty shelf... ;-) until you click on them again (or reload the page).

2. Display only books registered either by shelf owner or by you.

First click shows only the books registered by shelf owner. Second click shows only books registered by you (to be precise: The user who's logged in). Third click displays normal view again.
When looking at your own shelf there's no difference between first and second click of course.

3. Compact shelf listing: Displays only lines with title and author.

Using this bookmarklet reduces the details shown for each book to one (or two) line(s) with only the title (and author / category). Handy for printing a short list e.g. for comparing your real and your virtual book shelf.
This bookmarklet currently is a bit "raw". Especially behaving different on screen and on printout.
Clicking again recovers all details.
Still have to refine this one...

4. Convert BX time to your local time.

On bookcrossing.com times are given as "BX time" which currently is Central Standard Time (CST) or Central Daylight Time (CDT) respectively. This bookmarklet converts all such times on a page - e.g. in forum posts or journals (Release times!) - to your local time.
It requires the clock and timezone on your computer to be set properly.
It may take a few second on slower computers and large pages.

---> Instructions, Installation

Just do a right click on the appropriate link and chose "add to favourites" or "add to bookmarks" (or whatever it is called in English and in your browser).
Even more easy: Drag the link into your favourites or bookmarks bar (not possible with some versions of Internet Explorer).
It's of no use just here to click on these links! Nothing sensible will happen, but maybe this very page will change strangely...
Javascript must be allowed in your browser for any of these bookmarklets to work!
Move your mouse over this text. If it turns read and afterwards changes to green your browser allows Javascript.


Tested with Firefox and Internet Explorer 6.
Please don't hesitate to send questions, bug reports, suggestions by PM or email!