It's not going to win any design awards, but BitMeter 2, a program for monitoring your PC's bandwidth usage, offers a nice set of features. BitMeter 2's floating graph with simple text displays for real-time downloads and uploads is easy to follow. You can customize the display's color and transparency.
Considering its size, BitMeter 2 provides an impressive amount of options and information. You can view summaries of network activity with hourly, daily, and monthly breakdowns, or receive audio notifications that can be set by transfer size and direction. The built-in calculator is useful for computing the speed and size of download and upload activities. You can create automatic or manual backups of the program to easily restore history and settings, and there's an ISP Restrictions configuration panel that can configured with a minimum of hassle.
This freebie is easy enough for any user looking for a simple and effective tool for monitoring network activity.