REST Yourself

Representational State Transfer (REST) is a style of software architecture for distributed hypermedia systems such as the World Wide Web. The term Representational State Transfer was introduced and defined in 2000 by Roy Fielding in his doctoral dissertation. Fielding is one of the principal authors of the Hypertext Transfer Protocol (HTTP) specification versions 1.0 and 1.1. -- Wikipedia

With this Mystery I wanted to do something differently. I could have made a simple and dry multiple choice test about this topic, but I wanted to do something for real. So I created a real working web application where you can test your REST skills live and get immediate feedback.

What is needed?
This mystery consists of 10 tasks, which need to be performed against an example geocaching REST API. Each successfully performed task gives you a hint for the final and the next task description.
The 10 Tasks form a short geocaching story:

1. Open the application root ressource
2. Look for Pocketqueries
3. Create your own Pocketquery
4. See the Pocketquery result
5. Open a cache listing
6. Retrieve the logs
7. Refresh the logs
8. Post your own log
9. Correct you log message
10. Cleanup your Pockequery

You need to perform proper HTTP requests, know HTTP methods, status codes and headers. It's also necessary to be familiar with media types like XML and JSON.
The 10 tasks build upon each other. So you need the previous responses to perform the next task.

Constraints
This API is minimalistic and only designed to work with the exact task you are about to perform. If you are curious, you might try other calls, but don't expect them to work.
It's completely stateless and doesn't remember previous requests. If you make a mistake: just try again.
It talks XML only, so be precise (and simple) with your requests!

Task 1
Call this URI: http://restyourself.appspot.com/exam/geocaching and ask for the xml representation of this ressource.

Final
The final coordinates can be calculated like this: N 50° AJ.(E+2)H(G-1) E 008° (B+1)(C-2).(D-1)(F-1)(I+1)

The cache contains among other small items a book about REST as an award for the FTF!
Please hide the box properly after you've found it.

Many thanks to the Betatesters ElKidd and sunschein.

Congratulations to stimpy23 for the FTF, we4geo for the STF and JoJomau for the TTF

Update 14.06.2011 21:13:
Thanks for die_karoettchen for feedback. I've updated the description and the error response of Task 1.

Update 17.03.2011 21:50:
Thanks for all the valuable feedback. I've incooperated your suggestions and reworked Task 3 and 8. There was some room for missinterpretation.

  PrefixLookupNameCoordinate FI FINAL Final (Final Location) ???    Note: