Comcast has thrown down the bandwidth gauntlet. Starting in October, Comcast broadband users will be restricted to 250GB worth of downloads per month. When asked whether the cable company was planning on offering a bandwidth meter to customers, a Comcast representative stated that it hopes to, eventually, but until then Google would be a nice place to find one.

So, I've come up with a list of free bandwidth monitoring software for Windows and Mac that should tide you over until Verizon brings some Fios action to your hood.

BitMeter offers a Web interface for tracking your traffic through a browser. (Credit: CNET Networks)

First off, let's look at BitMeter. When running, it lives in your Windows Taskbar, so the features are accessible only through the context menu. Halfway down the lengthy list is the knockout punch: ISP Restrictions. This lets you set a limit that can be based on downloads only, or total traffic. It also offers notification based on the percentage of your quota that has been downloaded, and the start date of the quota.

It's more than a one-hit wonder, offering a live graph of upload and download usage, a usage calculator that can work based on transfer time or file size, and hourly, daily, weekly, and monthly statistics. This data can also be exported and saved. However, BitMeter lacks polish in the interface. The main screen is a live usage graph. All features are hidden in the context menu, so it's not going to win any design contests soon.

BitMeter's ISP Restrictions window. (Credit: CNET Networks)

Despite the promising name, I found Bandwidth Monitor Lite to be a disappointment as far as monthly quotas were concerned. Similar to BitMeter in layout, although the look of its graph is slicker, the actual tools that the Lite version offered were slim. You can track the amount of data downloaded and set a day of the month to start counting, but there was no way to set the quota or configure an alert.

The persistent emphasis on themes and skins was irritating, since the features that they were meant to put on display were less than stellar. The upgrade version does offer a lot more, but paying for a bandwidth tracker strikes me as a bit insulting, since we're already throwing cash at Comcast that we might not have had we known there would be a post-contract download cap.

Two other promising tools that I looked at were Axence NetTools and FreeMeter. Axence was the more advanced one by far, with a well-organized and professional-looking layout, but neither has bandwidth-monitoring capabilities that Comcast users will be looking for. Axence does have a "bandwidth monitor," but it can only check on user-specified connections, not overall up/down traffic.

For Macs users, iStat Menus and MenuMeters both sounded promising. Neither offer the robust bandwidth management tools that this Comcast problem is calling for, though.

I did that find a little-known app called SurplusMeter does precisely what we need it to do. Like BitMeter for Windows, it gives users the ability to set a bandwidth limit, a start day of the month, and the connection type--PPP Modem or Network Card, for example.

SurplusMeter offers Mac users a clean and simple traffic tracker. (Credit: CNET Networks)

SurplusMeter also calculates a daily allowance, and reconfigures that depending on how much you've actually used for the month. It lacks the not-quite-fancy graphs that I encountered in its PC counterparts, but SurplusMeter also lacked something they had: an alarm or notification that would tell you when you were approaching your limit.

Fortunately, the interface is dead simple. All the options are presented in an uncluttered layout--you'll get exactly what you need from this app with a minimum of hassle. Handy progress bars give a slight visual flair to the days left in the month, the download megabyte count, and the total downloaded and uploaded.

Clearly, there's no killer app for either operating system, but there's at least one for each out there that most users should be able to get by on. It's an imperfect stop-gap to a problem that has the potential for wide-ranging consequences far beyond mere file sharing.