12 Oct 2007 at 08:28 - 5
Well, I took part in all the beta weekend events, so I'll tell you what I remember.
The first beta event, E3 for Everyone, took place in May 2004 and was open for everyone. This was followed in September with the World Preview Event which was also open for everyone, I think.
Subsequent events were a mixture of completely open and requiring readily available keys from various sites or the key from the preorder pack. Each lasted a weekend (3 days to cover all timezones), and were spread 1-2 months apart.
Because the events were spaced apart and short the districts were generally pretty full. It also meant there could massive changes between events, including character wipes. The events also allowed easy access to features that otherwise would take some time to obtain, such as allowing you to start at level 15 or 20 in Lion's Arch, or the infamous Unlock All Skills for PvP characters. There was a limit to how much PvE content you could reach though - I believe it stopped before the desert and sent you to the Tomb of Primeval Kings instead. It varied from event to event though, in the first event you could only do Ascalon, in other events you couldn't reach Ascalon. The Northern Shiverpeak missions were under-developed for most of the events, so people had to trek through the explorable areas to reach LA from Ascalon on some occasions.
Ah, good times. So much has changed, both in the game and in our understanding of how things work. Skill gems and skill rings, the temporary 9th skill slot, technicolor Moa Birds...
In addition to the beta weekend events, there was a relatively small closed beta group. I don't know the details of how things worked with it as I was part of it, but I do know they had regular times when all testers were supposed to show up.