OK, I have taken the plunge and ordered a SanDisk Extreme III CF card (133x card) that has ~20MB/sec Read and Write speeds with the intention of replacing my internal 4Gb Microdrive on my Zaurus.
I chose this card because it seems to offer good value for money (about £140 GBP in the UK now), top performance, and a 10 year manufacturers warranty.
Note that there is a Transcend 8Gb card also available for about the same price now, however, the warranty isn't lifetime it is 1,000,000 write cycles and the operational temperature is lower.. I decided to err on the side of caution therefore and go with this card which is known to have write spreading technologies and may yield a considerably longer life (maybe).
I also didn't need the 8Gb version because all my Multimedia stuff is on my iPod.. I prefer to do it this way then at least when the battery is dead from listening to music and watching movies I still have my Zaurus
I believe the write levelling on this card will probably (even with constant running) see out the life of this Zaurus but I guess that only remains to be seen.
When the card arrives I will do some benchmarks and provide some information on runtime with both the original Microdrive and this card fitted since the power consumption is also supposed to be a fraction of the Microdrive.
Benchmarks will probably come first since I can perform those with the card in the additional CF slot.
but daaaaamn, I'm going to ruin my 'uptime' figures. I get disappointed if I have to reboot it more than once per month
(btw. in case you are wondering why I have been quiet here it's because my Zaurus 'just works ' and does everything I need it to at the moment... currently it's even running Ruby on Rails with MYSQL - it will be nice to see what performance is like with the new drive for this)