I was working in London at the time, it was a pretty shocking day tbh, we were locked in our building in Soho for hours. It was the day after we won the bid to host the 2012 Olympics and I can remember them just locking the gates to get down onto the Tube station and people moaning about how we couldn't run a Tube system how would we manage the Olympics!
Walked down past Tavistock Square before the bus was blown up, down towards Euston, then heard a bang!!!!! I can remember a fire engine pulling up and asking one of the firemen who was hanging out of the window what was going on, his answer was a "I don't really know what's going on mate"! People were really jumpy by this point, didn't really stop until I reached office in Soho. stopped briefly to look at some TV reports on the shop windows in Tottenham Court Road.
We were locked into our building and we just drank coffee and watched the news, late afternoon we were allowed to leave the building and people started to make their way home, nothing was running so lots of people walked miles. I made my way back down to Kings X even though it wasn't open and sat in a pub across from the Station and swapped stories with strangers.
When Kings Cross finally re-opening at around 19:00, it was full of armed police but was pretty deserted, it was like something out of 28 days Later! Normally commuter trains are pretty silent but everybody was chatting and recounting their experience of the day, us Brit's are are a bit weird like that!
Was back to work the next day but didn't get back on the tube for a few weeks, just used to walk from Kings X to Soho

It certainly had an emotional impact on me for some time afterwards, while statistically the chances are very slim you do think about "wrong place wrong time", especially as I was so close to some of the incidents, I guess that's exactly why terrorists do it.
A few days after on 22-Jul-05 poor Jean Charles de Menezes was shot and killed (RIP), certainly London was a pretty jumpy place for a while after.