As one window opens...

If it's the end of January, it must be the end of the second trading period for each of the Premiership clubs. After today, no more players can be purchased until the summer hiatus, so who's put their hands in their pockets since the start of the month and why?

Well West Ham have been most active - unsurprisingly and with some justification. With new owners willing to spend much of their hard-earned fortune and a team that's lacking quality and confidence, it wasn't exactly a bolt from the blue when new players started arriving through the gates of Upton Park.

Among those joining the payroll at West Ham were Luis Boa Morte from Fulham, Lucas Neill from Blackburn and just today, Matthew Upson from Birmingham. Boa Morte has already injected some much-needed pace to the team, but Neill is now injured and could be out of the side for a few weeks.

Aston Villa have made a couple of eye-opening acquisitions. John Carew is a regular scorer who's done well at Valencia in recent times and Ashley Young has left behind Watford to join Martin O'Neill's team that has slipped well into the bottom half of the table of late. He'll be hoping both will bring more in the way of goals than Milan Baros did - he's been sold to Lyon in exchange for Carew.

Blackburn have sought to bolster their defence with three new signings. Liverpool's Steven Warnock, Christopher Samba from Hertha Berlin and Basel's Bruno Berner all come in along with David Dunn for a second stint at Ewood Park to try and push Blackburn back into the top half of the table.

Suffering Charlton have brought in Zheng Zhi from China on loan - he's their international captain - and they've also punched their weight by bringing in Ben Thatcher from Manchester City for £500,000. Will it be enough to save them from relegation by the end of the season?

Neither Arsenal or Chelsea have seen the need to bring in anyone new to their squads but Arsenal have surprisingly offloaded Lauren to Portsmouth. The Cameroon international had slipped down the pecking order under Arsene Wenger but Harry Redknapp knows a bargain when he sees one and may yet give Lauren a chance to shine at Fratton Park.

Everton have cast their net abroad to pick up a couple of new midfielders. Their push for a UEFA Cup spot will no doubt benefit from the arrival of Anderson da Silva, the Brazilian who joins from Montevideo on loan and Portuguese international Manuel Fernandes who arrives on loan from Benfica.

Leaving Goodison is Simon Davies whose impact hasn't quite been as big as was hoped. He joins Fulham along with Clint Dempsey, American international, former Chelsea, Charlton and Portsmouth star Alexei Smertin and Italian veteran Vincenzo Montella, who's already started scoring goals for his new side. It might just be the winning combination Chris Coleman's been looking for as he tries to keep a foothold in the Premiership for another season.

One of the most notable signings has been Henrik Larsson's short-term move to Manchester United. He, too, has started paying back some of the money Sir Alex Ferguson splashed out and it'll cross his mind that an extension to his stay could be worth looking into come the end of the season.

Over at the Riverside, Middlesbrough have put the emphasis on removal rather than addition. Out goes a trio of recognisable names - Ray Parlour, Ugo Ehiogu and Massimo Maccarone. Tottenham have also released some high profile players in the form of Edgar Davids (who goes back to Holland and more specifically Ajax), Reto Ziegler and Calum Davenport - one of West Ham's other purchases.

But aside from all these purchases, one thing may have escaped your attention: an increasing trend for signing celebrity names. SPAOTP can confirm that Manchester City have signed Michael Ball in a move that will test every fan's resolve, and Reading have snapped up Alan Bennett which should also get numerous heads talking.

Oh and one more thing: don't tell the chairman of Blackburn Rovers about Everton's latest signing. It's Mark Hughes.

I didn't realise he was still playing...