Scan files with 35 virus scanners at once

Virus Total

With this cool online virus scanner you can upload individual files (up to 20 MB i believe) and have them scanned. The cool thing is that it scans the file that you uploaded with 35 virus scanners, so it's way more accurate then scanning it with only one program. I use this all the time with suspicious-looking files that I download. You can also scan files by emailing them as an attachment to scan@virustotal.com with "SCAN" in the subject line.