I am Operations Team Leader at Yola.com. We are a small team of four guys who are currently doing a complete re-platform to get rid of all the technical debt that has built up in the last three years. We're moving our code from svn to git, using chef on all our machines, and re-architecting all the services, and it's pretty exciting.
Currently celery, the Distributed Task Queue (http://ask.github.com/celery/index.html). I'm replacing a lot of old crufty ways of running periodic jobs and getting background tasks done (sending to SQS, and then having a cron job sit and munch through the queue, for example) with a simple system of celery tasks. This way, each of our services can fire off a request to any one of the others that will get queued and dealt with at the target service's leisure, but we can also bring up a cluster of generic workers that can handle all of our other task requirements. I might be a little too starry-eyed about it, though: it's starting to look like everything is a task I can put into celery ("when all you have is a hammer...").
It may sound like I'm sucking up, but CodeConf in April this year just blew my mind. I was in a bit of a funk at the beginning of the year, I wasn't getting anywhere with work, and things just seemed a bit grim. My boss bought me a ticket to the conference, and I flew out to San Francisco (from Cape Town), and rocked up to see what was happening. It was just unbelievable.
Quite apart from the energy that the Github guys brought to organising it (not to mention the open bars every night and meals provided), the other attendees were great. Being limited to 300 people meant that everybody was invested and excited, and I was really cheered up by how keen everybody was. The talks were, of course, fantastic, but my favourite example of how great the conference was was when somebody hacked together the heroku app so that people could see where the spare seats were in the conference venue. He threw it together in an hour on Saturday morning, and by the afternoon, a bunch of people were forking it, adding features, fixing bugs, sending pull requests, and generally just jamming code together - it was really inspiring. I remember actually sitting there with a big grin on my face, going "oh yes. I remember when coding was fun. This is why I got into this field in the first place".
There was also all the quirky little aspects of the conference, like Github sneaking the release of Issues 2.0 into a lightning talk under disguise as a bot demonstration, and it really re-energised me - possibly the start of the awesome re-platform work we're doing now.
I'm not a pure hardcore developer - my work requires quite a wide range of tools. Lots of shell scripting, of course, and ruby for chef. However, I have been using python as my primary scripting language since 2004, and I consider myself well proficient in it - if there's anything bigger than ten lines of shell script, it becomes a python project. Tiny web apps are done using bottle.py (http://bottlepy.org/), and big ones are done in Django. I am the owner and a lead developer of a python bot project which I think is pretty cool (see https://launchpad.net/ibid). So, I'm no Guido van Rossum, but I think I do pretty well.