We don't have a baby monitor; it's not possible to get out of crying earshot in our apartment. So on our last visit to grandma's capacious (i.e., 2-story) house, I called one of our family-plan mobile phones from another (unlimited in-family calls, yo), and just used my cell phone headset to listen for crying. It worked just fine.
BÈbÈtel is (probably) a French product, but it's for sale in the UK, and it looks awesome. Just plug it into a phonejack, program your landline, mobile, or pager number into it, and it'll call you when your kid cries. All those baby monitor problems (out of range, your neighbor's cordless) are gone, replaced with cell coverage problems ("Can you hear me now?").
Here's "a common scenario" BÈbÈtel is designed to solve:
Youíre staying in a hotel with your small children or baby who are sound asleep in the room. You want to go downstairs for some dinner or a drink at the bar but do not want to leave them alone. Your regular baby monitor just doesnít have the range or could experience interference.
According to Mark at Sparkability, who clued me into BÈbÈtel, the company has no plans to enter the US market because of the prohibitive costs of recertifying all the manuals, testing, etc. [That, and New York City's finest'll throw any delinquent Europarent using it into the slammer.]