You may see fewer than usual blog entries this week because I’m vacationing in Ocean City, Md. I couldn’t deprive you of this regular feature, however, so I’m going to tell you about a free utility I often use while vacationing – iStumbler.

I take my MacBook with me whenever I travel. Although I might use it for work (you’re reading the proof of that), I also use it to transfer all my digital photos, check the local weather forecast and even locate area eateries. Many of these activities, you probably noticed, require an Internet connection, and that can be an issue. I’m often astounded at the erratic state of wireless Internet connectivity in the hospitality industry. Some places provide it free, some charge a fee and some offer noting but a “data port” plug on the phone, as if you would even consider using dial-up. Let’s please move into the 21st century, OK?

A Mac user traveling under these problematic conditions can almost always use a little help locating free wireless Internet, and that’s where iStumbler comes in. It’s true that any Mac laptop of recent vintage can automatically detect compatible wireless networks, but the built-in Internet Connect Utility provides limited information, particularly the critical bit about whether it’s an open or closed network. You can’t access a closed network without a password -- and you shouldn’t try, since the network owner obviously doesn’t want outsiders pirating his Internet connection.

iStumbler shows you any open networks within range along with its signal strength as a percentage, which is far more accurate than the Airport icon in the Menu Bar or the meter in the Internet Connect utility. Better still, iStumbler shows the signal noise (interference) for each network, as well as its channel and MAC address (Internet Connect gives you the MAC address as well, though it’s called “Base Station ID.”)

The creators of iStumbler did so to help Mac users find open public networks, which are the kind you can use with a clear conscience. That said, the software does just as good a job finding open non-public networks, such as those set up in private residences. Whether you decide to piggyback on someone else’s network without their permission is a personal decision -- you’ll almost certainly get away with it – but you’ll have to live with the guilt.

iStumbler has two more abilities I have not had cause to try: it can search for Bluetooth devices and can use Apple’s Bonjour feature (which allows devices on a network to “see” each other automatically). But I consider iStumbler’s primary function of locating Airport-compatible wireless networks enough to make it an indispensable app on my MacBook. And yes, it is Universal Binary, which means it can run natively on both PowerPC Macs as well as the current Intel-based models.