The cache idea is very interesting. What would you put in the cache? I suggest it be inexpensive items so if the cache is discovered and raided, you can inexpensively replace it.

1. Firemaking equipment. Some waterproof matches in a small ziplock bag. A bic lighter, a flint style firestarter and tinder (http://www.backpackinglight.com/cgi-...ter_basic.html), some dry kindling, etc. A small cable saw to cut wood into manageable sized pieces.

2. Protection. Space blanket, or perhaps a space blanket style sleeping bag which would provide a better protection from weather when exposed. If there's room, maybe a cheap jacket from walmart. I've seen some real inexpensive fleece jackets there. Combined with a space blanket for wind protection, the two would really help. Maybe a pair of thick wool socks? A cheap blue foam camping pad to sit or lay on and provide thermal insulation.

3. Food. Not generally required for short durations but a good morale booster. Something that can be easily eaten even if frozen so it needs to have a low moisture content. Perhaps some high sugar cereal, crackers, or Clif Bars. Food should be stored in a vapor barrier bag to reduce attracting animals.

4. Signalling. Perhaps a couple fold up triangle reflectors that can be put in each lane of the road to help flag down a motorist coming either direction.

5. Light. A small LED squeeze light. Warm up before using by putting in a pocket so the battery will be at full power.

6. Medical. One of the many small backpacker emergency medical kits should suffice.

7. Bike stuff. A fold up spare tire. Spare tube. Duct Tape. Some wire. String. A cheap knife.

So you can find the cache, perhaps wrap a bit of reflective tape around a highway sign post and secure the cache perpendicular to the road some number of paces from the sign.