If you are flying to the UK, avoid London at all costs. Fly to Paris and take the train -- it will probably be faster. As usual (this is the third time I have been through this recently), several hundred people in line at passport control and one person working it. I waited an hour (and I was in the first 100 or so people). Was grilled for 15 minutes on why they would want me to come and speak to an audience in the UK. Once I mentioned blogging, I was given the benefit of my interrogator's opinion on the subject (dangerous, bad). Missed my connecting flight (my first flight was an hour late, plus the hour in passport control) and had to pay a big fee for a new ticket as it wasn't the airline's fault I didn't get through passport control in any kind of timely fashion. If you have to go through this mess, make sure you leave transfer times of at least 3-3 1/2 hours. And you'll wait another 30-40 minutes to pass through security...again.
And the whole liquid/gel thing? Well, it includes things like lip balm and face powder. No dangerous cosmetics** allowed on the plane (but they will mail them to you if you just happen to have a stamp...sigh). But don't expect the rules to be applied consistently across the UK. It depends on what management company runs the airport. So if you are transferring, you should do your research as to what you can actually take on the plane and what you can't, based on each location you will be traveling through.
My cry for sanity: Why oh why can't rules be applied consistently across the country so we know what to expect? How about across an airline company? Case in point: One carry-on bag on the plane. Totally enforced in Edinburgh (the size of a small briefcase). Could get away with 2 in London Luton. In Paris, I saw quite a few people with 3. Arrrgh.
**And what happens when you are traveling to a meeting for the day? Women are judged on their appearance, and fresh faces are part of that. Take away my powder and lipstick? Grrrr. Expect to spend $50-70 in duty free for new makeup you will then have to throw away before you return home (unless you have that handy dandy stamp - who checks baggage for a one-day trip?). Give me a break. Can you really make some kind of explosive that resembles pressed face powder?