Before you deploy a production environment, it is always best to have a test environment available to test settings, try out new software or patches, or simply to practice your Asterisk skills.
For this environment, you can go with an inexpensive solution such as PIII 512 MB PC or better. Another solution is to use a virtual environment in which your PC can virtually host another operating system within itself. An excellent and free virtualization software is VMWARE Server edition (www.vmware.com/products/server/). This software will easily allow you to load ISO files or boot from a CD and install a complete Asterisk system on your local PC.
One thing to keep in mind about test environments is that they are often used for testing functionality. However, quality testing will prove difficult if your test environment is not of the same make as your production environment. For example, virtualization software often requires a great amount of memory and will be sharing...