Question: I'm looking for an easy way to debug RESTful services. For example, most webapps can be debugged using your average web browser. Unfortunately that same browser won't allow me to test HTTP PUT, DELETE, and to a certain degree even HTTP POST.

I am not looking to automate tests. I'd like to run new services through a quick sanity check, ideally without having to writing my own client.

Answer: 
At my firm we use a variety of different tools and approaches to testing RESTful services:

* We write [cURL](http://curl.haxx.se/) scripts - essentially a single command saved in a file. One file per resource per method. For PUT and POST, we'll usually have files containing the representations to send alongside the cURL script. For example, for a mailbox resource, we might have a file named `mailbox_post.cmd`, which might contain the line `curl -v -X POST -u username -H 'Content-Type:application/xml' -d @mailbox_post.xml http://service/mailbox`. We like this approach because we end up building a collection of tests which can be run in a batch, or at least passed around between testers, and used for regression testing.
* We use cURL and [RESTClient](http://code.google.com/p/rest-client/) for ad-hoc tests
* We have the service serve XHTML by default, so it's browsable, and add forms resources, so the service is actually partially or fully testable using a browser. This was partly inspired by some parts of [RESTful Web Services](http://oreilly.com/catalog/9780596529260/), wherein the authors show that the line between web services and web applications may not need to be as solid and strict as is usually assumed.
* We write functional tests as [Groovy](http://groovy.codehaus.org/) closures, using the [Restlet](http://www.restlet.org) framework, and run the tests with a test runner Groovy script. This is useful because the tests can be stateful, build on each other, and share variables, when appropriate. We find Restlet's API to be simple and intuitive, and so easy to write quick HTTP requests and test the responses, and it's even easier when used in Groovy. (I hope to share this technique, including the test runner script, on [our blog](http://blog.arc90.com) soon.)
If you want free tool for the same purpose with additional feature of multipart form data submission it is here <http://code.google.com/a/eclipselabs.org/p/restclient-tool/>