Ushahidi's Patrick Meier has a fantastic graph of deployment time for Ushahidi's amazing crisis-mapping solution (which has been deployed for such diverse projects as Haiti post-earthquake, the Gulf Coast post-BP, and DC's 2009/10 "Snowmageddon"):
The simplicity of Ushahidi setup sometimes leads to some crestfallen administrators.
Just because you bought a domain name and ran the Ushahidi installer doesn’t mean that anyone is going to use they system — and even if you somehow get a lot of reports, you might not be relevant to the existing systems [...] Ushahidi is only 10% of solution.”
I'd posit that this 10%/90% division applies to any and all "tech" solutions to real-world problems.
The technology is increasingly (perhaps it always has been) the easy part. It's a shiny, tangible product with clear "milestones" of in development, in testing, deployed, working. Lots of happy checkboxes for any M&E report, and photo-ops to generate great press and build excitement and community around a technology.