Here is a list of some things that it might be sensible to bring with you in order to make a trip to an h2g2 Official Summer Party all the more comfortable. It's not comprehensive, no items are required, but it's here as a simple list of suggestions.

1. Drinking Water

   Easily the most important item to remember, especially if it's going to be sunny. Remember that it's about 3 hours or so between the beginning of the outdoor event and actually hitting the pub. One 500ml bottle might not be enough. One of the cheapest ways to buy bottled water is to bring masses and share it with people who have cups. Sainsbury's sell 5L bottles of mineral water for about £1, but they're not too strong and water is quite heavy.

2. Suncream

   Even if you intend to get a nice tan, if the sun's bright, 3-hours will burn most people. Bring suncream, or risk having to confine yourself to the shade.

3. Sunglasses

   A pair of shades is a good idea. You protect your skin - don't risk your eyes!

4. Food

   Bring something to eat - perhaps a sandwich or two for yourself and some snacky things to share. There's no need to go overboard, and I doubt anyone will mind if you bring nothing, but a few bags of crisps and some sweets can be a stunning icebreaker, especially if it's your first h2g2 meetup.

5. A Towel

   You can sit on a towel if it's dry. You can use it to dry off if you get drenched. You can fold it several times to make a cushion for your head to lie down and get some rest. And hey, you'd be a fool without one!

6. Travel Plans

   If you don't know London, get a map beforehand - most bookshops will sell you one, or find relevant bits online. If you don't often travel to and/or around London, plan your journey carefully. If you're using public transport, you'll be wanting to check your journeys with the operator. For trains, try National Rail. Transport for London includes a great journey planner for all public transport around the capital.

   At the very least, make sure you know the times of your last trains home. It wouldn't be fun to get stranded overnight with no accomodation.

7. A Watch

   It's a lot easier to avoid missing your last train back if you've got a watch, preferably with an alarm.