One of the most useful was the QRZ Gridfinder application. I could enter an address and it would do a great job of finding the grid locator for that address. Doing it by address is useful for those contacts on QRZ that get pulled into my log that haven’t provided a grid locator in their info. That QRZ Gridfinder app hasn’t worked since the latest QRZ.com site redesign back around the end of 2008. With it not working, I was going through a set of web pages to find a lat/long for an address and then convert that lat/long into a grid square.
When I posted recently asking if anyone was going to address that useful site feature and try to get it working again, someone posted an alternative to use until the page gets fixed (assuming it gets fixed at all). The alternative is using a site I’ve previously used for APRS. If you go to http://aprs.fi and if necessary provide your call sign as a login, you can enter in the address you want in the text entry address box on the right side of the map page and press search. It does a good job at finding the location. I usually just copy/paste the address from QRZ for the callsign I contacted and paste it in. More often then not it finds the address, but in some cases, you need to trim DX address info if it doesn’t know the specific street address, but it gets you close enough.
Once the address is found, you need to move your mouse over map point that is placed. The upper left corner of the map will show the lat/long and grid square of where your cursor is. Move your cursot (+ sign) over the bottom point of the map pin and you’ll have the grid locator.
I’ve asked if the site owner would consider adding the grid location to the pop-up bubble window that is shown when it finds the address and adds the map point. That would make it even easier and more exact if that enhancement is considered and added.