[LAU] VoIP advice?

[Ken Restivo]

I'm interested in using VoIP on Linux, instead of getting a landline phone or having to get slimed by dealing with the evil cellphone carriers and their lock-in contracts and shady "deals", etc.

What's best practices for VoIP on linux without any landline?

i.e.

1) What services are cheapest and most open for connecting to the PSTN?
2) What free/open clients are available that will work with them?

For example, do I need to run Asterisk or can I just use ophone and/or gnomemeeting or equivalent?

Almost all my calls will be going to/from the PSTN, and I'll only be making/receiving them rarely.

-ken