This page will give you the necessary lines for your tinydns "data" file, or your BIND zone file, to create the SRV records you should have for a Jabber server.
Note that the code which generates the records is entirely client-side Javascript. Of course this means that Javascript needs to be enabled in your browser in order to use this page. If you normally have Javascript turned off, or if use the NoScript extension for Firefox like I do, you will need to turn Javascript on if you wish to use this page.
An alternative might be to save the page on your local system and run it from there. Feel free to examine the code before running it- no data is sent back to my server, or anywhere else.
For tinydns:
For BIND:
This web page and the Javascript code it contains are licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.