Discussion on:

Five tips for using Web-based tools on your consulting jobs

DYNDNS has long been a favorite of mine, but some of the others are unique, particularly the default password list, saves time on Google. I also recommend OPENDNS.ORG for setting down internet security lockdowns, the basic free service can be used for homes but a paid account, and it is inexpensive, opens up white and black list management, simple to implement too.

I use http://www.mxtoolbox.com mainly for emails problems

When I need to work on machines remotely, I use LogMeIn (https://www.logmein.com/). They actually have MANY services/software to help with different problems.(https://secure.logmein.com/US/products/default.aspx/) Unfortunately it can get a little spendy. Their free program that I use -LogMeIn Free (https://secure.logmein.com/US/products/free/)- allows me to do pretty much all I need: Remoting the PC, WOL (if the PC supports it), chating w/ the client. I won't list the small things, but there is more. It only takes one program that needs installed on the Host, and everything else is Web-Based.

Here are two I use frequently:

http://www.robtex.com/dns/ - The level of detail you can get from this site is voluminous. Check out the graph tab after a search for a cool diagram.

http://www.subnetonline.com/ - I use this primarily for the IP4 to IP6 conversion calculator for new windows 2008 servers when there is no IPv6 plan of action. At least this way there is some set value for servers based on internal broadcast domains. But there are soooo many ip tools here it can really do a whole lot more.