- strace shows all syscalls a process does while executing. This makes it easy to find where things start to go wrong. I give an introduction at http://www.linuxintro.org/wiki/STrAce.
- disassembling: objdump -d shows what a program will do once it is executed in assembler language. This is also called disassembling. I show disassembling a "hello world" program at http://www.staerk.de/thorsten/Assembler_Tutorial#disassemble_it_2
- network replay: Using the telnet or netcat tool you can manually interact with a web service. You can test e.g. HTTP transfer and IMAP transfer, see http://www.linuxintro.org/wiki/Telnet
- network sniffing: What you can do to process execution you can also do with network communication. Use the tool wireshark, see http://en.wikipedia.org/wiki/Wireshark
- USB bus sniffing: You can use Wireshark to drill down on USB bus communication as well. Good for troubleshooting keyboards, printers and scanners.
- SCSI bus sniffing: Using the tool blktrace to dissect the communication of scsi commands between your hard disk controller and your processor.
- byte-by-byte disk analysis: Use the tool dd to read any sector or byte on your harddisk. Great for analyzing boot problems and for cloning harddisks.
There is another word for PsyComputing. How is it called? Write your answer to the comment section :)
