According to a local resident near Berkhamsted, England, filming for Harry Potter and the Goblet of Fire has been going on in the area for the past few days.
Russell Brown, a resident of nearby Beacon Hill, came across a "large film crew" and found that it was in fact Warner Bros., filming what appeared to be the scene where Harry, the Weasleys and the Diggorys meet at a certain portkey to get themselves to the Quidditch World Cup:
On Tuesday 27th and Wednesday 28th July 2004 I was happy to come across a large film crew on one of the hills just outside my village (Beacon Hill which is located in the Ivinghoe hills near Berkhamsted). On further inspection I quickly found out that it was in fact Warner Brothers productions, and they were filming the 4th installment of Harry Potter.
From where I was standing I was able to see the characters of Harry, Ron, Hermione, Ginny, Mr. Weasley, George and Fred Weasley, and what I have come to believe to be Amos and Cedric Diggory. It looked like they were filming the scene where they are travelling to the portkey, as at the top of the hill stood one large boot which all the characters were walking towards and all looked rather exhausted after the sixth take.
The main actors Dan [Radcliffe], Emma [Watson], Rupert [Grint], and Bonnie Wright all left the set at 7 p.m. on Wednesday and doubles stepped in and continued working till 8:30 p.m.
The Leaky Cauldron has confirmed this account through their usual reliable sources. The report exactly matches the book version of events:
"Well, have a lovely time," said Mrs. Weasley, "and behave yourselves," she called after the twins' retreating backs, but they did not look back or answer. "I'll send Bill, Charlie, and Percy along around midday," Mrs. Weasley said to Mr. Weasley, as he, Harry, Ron, Hermione, and Ginny set off across the dark yard after Fred and George.
They didn't have breath to spare for talking as they began to climb Stoatshead Hill, stumbling occasionally in hidden rabbit holes, slipping on thick black tuffets of grass. Each breath Harry took was sharp in his chest and his legs were starting to seize up when, at last, his feet found level ground.
Check out this collection of photos of Beacon Hill.