Other great node app hosting options include Joyent's SmartOS and Microsoft Azure. Both have a free trial period.
Azure can be a great learning platform for node.js as you can host your node app in Windows Server, Ubuntu Linux, or Azure's special "web site" shared deployment scheme.
http://www.windowsazure.com/en-us/develop/nodejs/tutorials/create-a-website-(mac)/
Another cost efective solution for node app hosting is Azure's "Web Site" approach - about $10 per month. The down side is that you have to use their shared environment that hosts your node app via IIS. In practice, this worked for well for me, but you are limited in that you can't use certain Linux functions from Node when it's running on Windows, and you won't learn how to configure the node service yourself, which may or may not be important to you. (Note: Azure's GIT deployment process works great if you want to deploy your app from a local GIT repository. Also note that NodeIIS will stop your node app when it's not in use for a certain period of time - and it auto-starts again when a request for your app comes in.)
Joyent's SmartOS platform is a Linux OS optimized for hosting your node.js app. They have impressive reliability and performance as well as great diagnostic tools.
http://wiki.joyent.com/wiki/display/jpc2/Developing+a+Node.js+Application
The most cost effective solution I have found so far is DigitalOcean, a great new hosting solution where you can host a full Linux VM for only $5/month! I have had great luck hosting Node apps there so far: https://www.digitalocean.com/pricing
