I have been scouring the internet for the last two days and have finally come up with a custom login form (understand: one doesn’t have to go through http://mycompany.basecamphq.com/login screen) to be deployed on almost every site (even WordPress 2.8+). I was reading the Basecamp forum, browsing through their API but to no avail. There are references to certain “Stickman’s method” and masses (masses! + more + here a little) of people looking for the very same solution. How does one embed/create their own login form to Basecamp on a 3rd party (one’s own) website?!
Well I’m very proud to say I have managed to achieve it. Partly by trial and error, partly through research. I have looked at libraries/wrappers such as “Basecamp PHP API” and “HTTP class for PHP“, both have their advantages but didn’t do what I needed out-of-the-box. I have studied these guys’ code and ended with a few (< 10) lines of my own solution which currently works. 100%. Bulletproof. I say currently because I suspect it might not be intended functionality of the authentication script. But I am also hoping that by the time 37 signals (Basecamp development team) change/disable it they will either PROPERLY describe how to achieve so (using PHP, no cURL and without using OpenID – which not everybody has).
Slightly hesitant to publish the solution not to bring Basecamp’s attention to it, but since I know there are LOADS of people looking for the solution I will tell you how. All I’m after is enough (say 25+) comments here requesting the functionality. Only then I will share. Promise! 
It is surprisingly easy, the only clue I’ll give you for now is to study the headers the login form sends and follow the redirections.
Demo will follow soon!
Can we have it please
I’m curious to see and eager to use on my site.
We would also find it useful. Please let us know when you publish it.
Let’s see it!
Don’t be coy! Give!
Oh, pretty please!
Psst…
Found this last night on github, posted by 37signals themselves, and works like a charm:
http://gist.github.com/255012
I need that solution too..
Yes please