The Ellington Hotel where the conference takes place is close to the Kurfürstendamm which used to be the Berlin boulevard during cold war times. While the Kudamm (the „official“ abbreviation) has lost its position which was taken by the East Berlin boulevards, it is still home of expensive boutiques, and as such you probably will not find much cheaper hotels in the close vicinity. If you want to look, however, here’s a list of some situated close enough to take a walk: kurfuerstendamm.de/berlin/hotels/
If you are looking for night life after the conference, you might want to look a bit more to the east. Mitte, Friedrichshain-Kreuzberg and Prenzlauer Berg offer food, music, dance and drinks all night (well, there is no closing hour in all of Berlin, but in these districts you won’t have to search more than a few minutes).
If you want some nostalgic flair the https://www.ostel.eu mimics a East Berlin (GDR) hotel during cold war times ;)
In general, public transport is quite good in Berlin, and you can expect bus, subway or railway waiting times not longer than a few minutes in these core districts, but I would advise you not to choose a district too far away from the center. Berlin’s public transport is a mixture of subway, S-Bahn (public railway), tram and buses. All share the same tariff, which means usually a ticket for 2,80 € (tariff AB) allows you to travel once from Berlin’s eastern to its western outbounds. See ticket shop and the journey planner. You’ll find a map of the transportation system here too.
You may buy a week ticket at the airport when arriving. Tegel is within AB range and a week ticket costs only 30 Euro and you can take U/S-Bahn, tram and busses anywhere.
And places to go? There’s simply too many of them. This site gives a good overview.
If you should be taking a walk around the Ellington, you will inevitably find the Tauentzienstraße which leads to the famous Kaiser-Wilhelm-Gedächtniskirche. Strolling around the Kurfürstendamm might lead you to the Story of Berlin museum (if you are interested in German history): story-of-berlin.de, and if you want some recreation and are into excellent tea I would very strongly recommend you to sip a cup of Berlin tea at kingsteagarden.de.
If you still can stand technology after two days of technobabble, the Deutsches Technikmuseum shows reconstructions of the first computers, Z1 and Z3, explained by the son of computer pioneer Konrad Zuse himself.
The historical core of Berlin is the Nikolaiviertel with the Fernsehturm, the Alexanderplatz and the Museumsinsel (island of museums) close by. IF you stay longer, taking a ship tour along the Spree allows a very different view of Berlin.
Nightly places to visit for dancers and young tourists are the arena-berlin.de (which is close to where I live, so if you want some guidance, join me after conference day’s end) and several clubs along the Warschauer Straße like the matrix-berlin.de. View the areas on Google maps – there’s literally something for every taste around.
Missing something? Just tell me!
Looking forward to see you in May