Many hotels now offer free wifi service, so you can skip using the expensive hotel phone, and also skip using your cell phone minutes. Especially when you are out of town, or out of the country, your cell phone provider can charge roaming minutes.
So, just buy an inexpensive headset with a microphone, and use one of the following services to make calls from your computer:
1. Skype - skype.com
2. MagicJack - magicjack.com
3. Your existing VOIP provider.
Have VOIP already ? Download a "soft phone", and you can use your computer to make calls. Just search google for "download soft phone" or "download sip phone". There are several free ones to choose from.