macintouch reports a cool way to avoid revealing one's e-mail address to spam spiders: encode the address as hexadecimal character entities. e.g. interface@p3k.org is encoded as

<ampersand/>#105;<ampersand/>#110;<ampersand/>#116;<ampersand/>#101;<ampersand/>#114;<ampersand/>#102;<ampersand/>#97;<ampersand/>#99;<ampersand/>#101;<ampersand/>#64;<ampersand/>#112;<ampersand/>#51;<ampersand/>#107;<ampersand/>#46;<ampersand/>#111;<ampersand/>#114;<ampersand/>#103;

simple, but efficient. and here's a quick rebol hack that does the encoding.