Virustotal.
Computer: Virustotal offers a free service of suspicious file scanning, using several antivirus engines.
VirusTotal
Art flash: Complexification.
Computer art flash: Complexification - Gallery of Computation.
Complexification
Software: Belarc Advisor.
Computer software: Belarc Advisor - builds a detailed profile of your installed software and hardware.
Belarc
Science: Find a drug.
Science computer: Find a drug. Help researchers find new drugs for Malaria, HIV and Cancer. Donate your idle PC time to a worthwhile cause.
Find-a-Drug
JDiskReport.
Computer: JDiskReport enables you to understand how much space the files and directories consume on your disk drives. Freeware.
JDiskReport