I've seen some of you mention traceroute, the first link on my list deals with wireshark a network protocal analyzer that puts traceroute to shame. It can tell you just about everything. The fact that it's made by CISCO doesn't hurt either (it could also be used to gather information to help you crack WEP encryption but you didn't hear that from me)
the second on my list deals with file, partition, and virtual drive encryption of amazing abilities, I store my tax records in an encrypted folder that has 3 layers of different types of 256bit encryption and uses a key file not on my computer to open:) I highly recomend it it's very user freindly and effective
http://www.wireshark.org/download.html
http://www.truecrypt.org/downloads.php