Is there simple service to store strings under my key that can be used by bots?

Requirements:

1. Simple command line access, automatic posting allowed
2. No need to keep some session with the service alive
3. I choose the key (so pastebins fail)
4. No requirement for registration/authentication (for simplicity)
5. The string should be kept for about a month.

I want something like:

Store:
$ echo some_data_0x1299C0FF | store_my_string testtest2011

Retrieve:
$ retrive_my_string testtest2011
some_data_0x1299C0FF

Do you have ideas what should I use for it? I can only think of using IRC somehow (channel topics, /whowas, ...), but this is too complex for this simple task.

No security is needed: anyone can update my string. The task looks very simple, so I expect the solution to be similarly simple. Expecting something like single simple curl call.