Just back from Barcelona. I enjoyed the city very much. Didn't have as much time to shoot than I first expected as I worked a lot there. But anyway, I guess I managed to have some interesting photo. Weather was a bit too hot for my taste and the light was quite harsh most of the time. I was fortunate to have a day that was overcast to shoot people in the streets. I don't have a wide angle for my M3 and 50mm was quite long for getting good architectural shoot. After this week of shooting wide angle on the digital and street on the Leica, I'm really craving for a wide angle in M-mount to leave the other at home.
I would like to thank you all for your recommendations, they were really useful. Now, let go back to the office to site in front of a computer and rest my feet so they can have a chance of curing all the blister I got walking all over the city.