iStat nano for Mac

From iSlayer:

iStat nano is our best ever stats widget, and it's free!

View detailed information on CPU, memory, hard drives, IP and external IP, bandwidth, CPU temperature, battery, uptime and the top four processes.

SysStat nano features the lowest CPU usage of any stats widget we've seen (compare it if you don't believe us, I'm sure you'll be pleasantly surprised!).

All view:

• CPU bar meter
• Memory bar meter
• Primary disk space bar meter
• In and out bandwidth
• CPU temperature

CPU view:

• Detailed CPU bar meter

Memory view:

• Detailed memory bar meter

Disks view:

• Detailed disk space bar meter for 2 drives

Network view:

• IP and total bandwidth stats
• External IP and bandwidth throughput stats

Processes view:

• A list containing the top 4 processes

Uptime view:

• Uptime and load averages

Battery view:

• Battery charge meter and remaining time (for supported systems)

Other features:

• 3 coloured skins (blue, black and red)
• Animated transitions when changing sections
• CPU temp in degrees Celsius or Fahrenheit
• A built in update checker, so you'll always have the latest version
• Very efficient code