I am always looking for goodies from everywhere. In addition to the pens, toothpicks, electronic parts and the like, I pretty much collect almost everything. Lighters are a great source of various springs, tubes, o-rings and assorted gadgets. Some care must be taken when taking them apart. The flint is spring loaded and can take out an eye, not to mention the fact that it contains butane under lots of pressure... Some of the other parts on circut boards look like cool cans or other parts, there are all kinds of nuts and bolts, some small enough to work in models, all kinds of wires, leaders, motor wrap wire, guitar strings, etc... The bubble packs for many of today's products are great for glass and such. Made cone shaped bezels for a 69 Torino with a punch, bubble pack plastic and a candle. I also and a regular searcher of model railroad supplies. Their nut and bolt details are perfect for adding those missing from kits. Not to mention an infinite of other tid-bits of just the right shape or material such as plastic bread ties, wires out of toy packaging, cigar pipe screens, computer parts, copier parts, electronic parts, fishing supplies, solder, aluminum house wire (made a nice set of headers from this and tubing).
Parts are where you find em. Just keep your eyes open and they just show up...