I've got the opposite problem, tons of ideas and not the coding skills to make them happen. I also have a knack for taking half-baked ideas and turning them into something viable.
That aside, my ideas come from observing things I and others do frequently (or want to do) that can be improved. Read rags, ask your peers what they do online,
Some examples from my list, I hope they spawn some ideas for you
My current attempt is for online book/paper editing spawned by my writing of a Security Handbook I want online and in deadtree format. Simple really: importing of documents (Word, ODF, RTF), browsable/readable display by chapter/section, WYSIWY{G,M} editor with revision/track changes, layout templates, exporting of content to to PS, ePUB, PDF. For monetization being tied in with publishers.
buying a house? tired of collecting addresses, realtor names and those MLS numbers? Geolocation + "bookmarking" and tie in to MLS database
"What is that song?" Recording song sample, identify unique artifacts (fingerprinting) and compare to database of known songs. Crowd sourcing would help here.
HTML5 Darknet. Websocket P2P network for a website, connect visitors and (selectively) allow chatting, sharing of bookmarks, play list, calendars
One more based on your question: a place for sharing of ideas that connects experienced developers to people with challenging ideas. :)
AS you can see, these come from common issues that people run into. Best of luck!