I believe it's 64 in the UK, CLKD.
I've not missed one either - I had some funny symptoms in early ‘89, when I was 22 - and had been having regular smears since I was 18, so went to have another one, early, which came back negative. The funny symptoms continued, so had another done in early ‘90 - came back with CYN 1 (pre cancerous cells) - had a colposcopy, which confirmed it, then laser diathermy in ‘June ‘90....smears again at 3 months, 6 months and 12 months post op - all clear. Was told by my lovely NHS gynae to have yearly smears for at least 10 years and if all remained clear, could drop back to 2 yearly. Which I have done. And will continue to do so (I do not trust the 5 year thing as there's still a chance of false negatives).
We read about that lovely Jade Goody here in Australia, and we had a couple of young women here who died before the age of 28 of cervical cancer - just devastating for them and their families.
Personally, I'm forever grateful that my very first gp insisted on regular Pap smears just after I became sexually active. They've never been uncomfortable for me, and I'm sorry for those ladies that do suffer having them done. For those ladies I advise to see another gp, there is no way you should have that much pain from a pelvic exam...