It took me 15 minutes today to write a simple full-text indexer for source code, using shlex and zodb. It accesses a 20Mb database below a notable delay. It will save me endless hours of using find/grep on the ~3600 header files I find myself searching pretty often.
Implementation time: 15 minutes. Retriever 15 lines of code. Indexer 37 lines of code. Time not spend using find/grep, priceless.