[Correction: An earlier version of this post incorrectly attributed the manufacturing of the Rescue Streamer. The actual manufacturer is named below.]
One amazing rescue story making the news rounds is that of Hiromitsu Shinkawa, a 60-year-old Japanese man who had been washed out to sea by the tsunami. Shinkawa, floating on a portion of his destroyed house's roof, was found floating nine miles off shore two days later.
During his ordeal, Shinkawa had somehow gotten hold of a long pole and tied a red cloth to the end of it to increase his visibility. Initially it didn't work: "Several helicopters and ships passed by, but none of them noticed me," he said, after finally being spotted and rescued by a Japanese Navy ship.
Shinkawa's clever thinking is echoed in an actual survival product designed for those lost in the wilderness:
The Hawaii-based Rescue Technologies Corporation manufactures the RescueStreamer, a passive signaling device that is essentially a gigantic HDPE plastic banner tightly compacted down to carrying size. The brightly-colored Rescue Streamer can be unfurled to "[provide] a substantial increase in a person's visual target size, ranging from 50 times to 240 times enlargement" and comes in all-terrain and aquatic (floating) variants.