Christina Wodtke has created Widgetopia, a growing collection of interface widgets and UI elements culled from sites around the world. Christina supplements the list with her own commentary discussing the merits and weaknesses of each device.
On the macro scale, Web Design Practices does a similar job illustrating current solutions to (mostly) e-commerce applications – how global navigation os shown, how the shopping basket metaphor is applied, how account management is dealt with and so on.
Conversely UI Patterns and Techniques advocates best practices for interface issues (standalone and Web). It succeeds in doing so, not in Nielsen-like prescriptive manner, but with balanced explanation, illustration and discussion. Well worth a bookmark.
In the e-commerce arena, the same design hurdles are encountered again and again – how to lay out a screen, where to put the sub navigation, how to implement search etc. While we can look at best practices and common practices (not necessarily the same thing) to find a prior answer to the problem, surely it’s more beneficial to pick the best bits from existing solutions and apply them to the particular issue at hand.
Christina came up with a great metaphor for this approach. When attempting to cook a meal I’d not tried before, I (like Christina’s husband) would trawl through half a dozen or more recipes and end up with a composite recipe which my kitchen experience tells me would work (and probably based around what I had the fridge). It makes sense to apply the same principles to interface design.