A while ago Google changed the user interface for your contacts. I’ve defined a group for every one of my D&D campaigns. The new user interface looks fancier and is less useful than the old one. Slowly Gmail is being bogged down by cruft: There’s menus hidden on buttons, actions triggered by clicking on links, and these can be above, below, or to the left of the main pane. It’s confusing.
I decided to renew my Xbox Live account. My credit card had expired. Pick the gamer card, account management, membership, payment options… And I ended in a sort of loop: I could redeem codes which I did not have, add a card (which I tried to do but at the very end the system refused it because “it already existed”) and look at my existing credit card. Only after having wasted enough time did I realize that on the screen where it shows you the card you can pick payment options if you want to edit the card, and that’s on the blue button. Everything else is on the green (select) or red button (back).
KathySierra asks in her latest post how we can get users to really use all the features the product has to offer.  Some people have responded that as long as the product does what they want, they don’t care about any of the other features.
So I drew this:
Generally I think it is more interesting to improve the documentation or discoverability of the existing product to get users to do what they want, instead of expanding the feature set of the product to allow the few power-users (or only the developer of the tool!) to do all the things they want.
Discoverability is a part of usability. It allows users to skip reading the manual. Knowing more or less what they want to do, they can use the tool with basic skills such as reading text and clicking links such as to better learn what they might want to do and finally do it.
Usability problems abound – not only on the web but everywhere. Jakob Nielsen has a good piece about navigation aids in cars and remote controls. 
I can personally identify with remote control issues. I like to listen to music when I go to bed. Most of the time I’m using the remote control, it’s essentially dark in my room. And there not many positions I am willing to memorize on my remote control. The sleep button is one of them. But sometimes I also want to find stop, next or previous! But guess what? I need to find the light switch first. One simple solution would be to put the five most important buttons on a row by itself, a row that you can find in total darkness. Those I might be able to memorize.
And if they’d be willing to hire me, I’m sure I could spend a few more minutes on this in order to help them improve usability by another 2000%.
The same goes for personal experience in mobile phones. I asked arround. All my friends recommended I buy Nokia because they are the “easiest to use.” And I did. And I never looked back. In fact I once tried to send a text message using a Motorola mobile phone and gave up after a few minutes. Hell!
UI design is becoming a big problem apparently. I read an article here  that talks about how it might be a good idea to get web people to create UIs since they work on this kind of thing a lot. I’ve recently been working on a web based tool and the number of problems that crop up is amazing. – NoufalIbrahim
Nice post by Matthew Thomas talks about usability issues in Max OS-X – they guys claiming to have the best usability… 
Yikes! What can I say? Define:pathological! :/