Sony has not dismissed the possibility of introducing a hard drive unit for PlayStation Portable, according to Sony Computer Entertainment Europe President, David Reeves, despite the impending release of the PSP Slim.

Speaking to Eurogamer this week, Reeves conceded, "I think that it certainly is not ruled out”, adding, "The only thing I would say is that the flash memory is simply so cheap - you can get an 8GB Memory Stick for under 100 Euros, and on 8GB you can get a lot of content."

"I think the big debate is - there's a point in time when you have to put a stake in the ground and say we're going to go with flash memory or we're going to go with hard drive. I don't think they've put that stake in the ground just yet," he explained. "So they're thinking about it - I think they'll get through Christmas and think about what the next step would be. You might hear more later."

Elsewhere, Reeves assured that the company is aware it needs to invest more in game software, despite it’s introduction of several new features at Leipzig this week, including satellite navigation and video-on demand.

He also highlighted the contribution that the PlayStation Network could provide, using the title Calling All Cars as an example: "On PSN you get an instant reaction - 'Calling All Cars, great game, okay, can I have it on PSP?' Okay, why not?", he said.