Espresso fix in River North?
(superior/lasalle area) Love a good espresso or cup of french roast at place that is low key with thoughtful (even if it is just BAR) service. Internet and food is icing on the cake and by no means manadatory. Coffee, first and last, is the thing.
Iguana Cafe on Halsted/Grand has internet, food and a great European atmosphere. It's not in walking vacinity but a short cab ride away. Also right down Grand is Sip Coffee house which also has great coffee (1223 W Grand)
For something right in the area of Lasalle/Superior, I'd start experiementing with various restaurants in the area (this is assuming you want to avoid the likes of Starbucks and Au Bon Pain)