Here's a walkthrough of 4sqNoGPS. Because the screen on the Opera Mini simulator is too small to show much, I used a web browser running on a notebook computer for the screenshots. Some scrolling will be necessary in actual use in the field.
4sqNoGPS uses the Foursquare API for everything so you can't do anything before logging in, other than read the "About" page. So follow that "log in" link.
4sqNoGPS uses Foursquare OAuth for authentication, so it sends you to Foursquare to authorize the application. If you weren't already logged into Foursquare, you'd be asked to do so by Foursquare. Because 4sqNoGPS uses OAuth instead of Basic authentication, it does not handle or store your Foursquare password.
This is the main menu after logging in. The first input field is where you can enter the coordinates. Because my phone doesn't have a full keyboard, I made it so that you only need to enter the digits in the coordinates. That shorthand is explained below the menu. So let's enter "394027753573" in that field.
Ta-da! It returns a list of venues closest to those coordinates. In this case, those coordinates are for a spot in the Pathmark parking lot. The venue "check in" link is next to each venue so from this page, you can check in at a venue in one step. Let's follow the "Pathmark" link to see the venue in more detail.
It's everything Foursquare knows about the Pathmark venue: address, category, tags, mayor, and tips. Specials would show up on this page too if the business has posted any. The Google Map is static but I may add some zooming/panning features later on. But wait! What is this "checkin with options" link?
This is an extended checkin form that allows you to add a shout message to the checkin and control whether the checkin status is sent to Twitter and Facebook. Also, setting the first option to "Don't show your friends" will make it an off-the-grid (undisclosed location) checkin.
4sqNoGPS also allows you to search for venues by keyword. (or by substring, rather, since you don't even have to enter a full word) Use the "Home" link to return to the main menu and enter "brid" at the "Search Venues:" field.
The result is a list of venues containing "brid". Naturally, it's a bunch of bridges and some venues that have the word "bridge" in their names.
Now, it's time to explain the "move to" links next to each venue. What that does is set your location to that venue's coordinates. This is useful sometimes if you've located the venue via keyword search or from your checkin history because it's quicker than entering coordinates. So let's "move to" Bridge Deepwater Food.
Presto! Now you see a nearest venues list around Bridge Deepwater Food.
Next, let's return to the main menu and follow the "History" link.
This is a list of 50 most recent checkins. Notice that each venue again has "checkin" and "move to" links. So if you revisit a venue, it may be easier to find it in your history and check in there.
The "Find friends" link in the main menu takes you to a page that shows you where your friends have checked in, from nearest to farthest.
The leaderboard is not actually generated by 4sqNoGPS. It's a page on the Foursquare website intended for Foursquare's iPhone app, but of course we can borrow it.
The "Badges" and "Mayorships" links lead to pages showing your badges and your mayorships. Nothing much more to say about those.
The last link in the main menu, "Detect location", is not meant for my phone. On browsers with geolocation capability, this will set your location to coordinates returned by the geolocation API and take you to the nearest venues page. For me, this may be useful if I'm checking in on my netbook using wi-fi.