VoIP is very reliable, most businesses actually use it for many reasons including the many features that come with it which you can't get from a normal landline.
Here is a highly recommended VoIP device that's very simple to use:
http://www.amazon.com/OBi110-Service-Bridge-Telephone-Adapter/dp/B0045RMEPI/ref=sr_1_2?ie=UTF8&qid=1361508407&sr=8-2&keywords=obi
It's worth noting that you can use a normal cordless phone or even use your computer to make calls, record them, setup voice mail.
I use Google Voice which is free however you couldn't get that in Switzerland being that I believe it's North America only as of right now.
Some other popular voip services that you may have in Switzerland include:
-Facetime
-Skype (should have this for sure, most popular but sometimes more expensive)
-Oovoo
-Cisco TelePresence
Note: With Google Voice you may be able to get it if you registered or used a friends US phone number and set your google account to US. That's only an assumption. I like it a lot though, it works on my cell phone, computers, and browsers very well.