Scrum Update

As we continue exploring Scrum at my workplace, we've started attracting observers, people from other teams who are interested in learning more about it and perhaps applying it to their own groups. Our team has some deviations from the standard Scrum implementation, which has prompted some questions. As food for future thought, it occurred to me that I ought to record those somewhere.

• No product owner. The product manager nominally responsible for this project is spread too thin, and has little or no involvement with the team. Most of the team is okay with this (it makes me nervous because it lessens accountability, which is one of the main goals of Scrum, I believe). We may be able to get away with it because the project is building a tool that will be largely used by internal people, at least in the early days.
• Two-week sprints. The suggested length is one month; we've been doing two-week sprints since the beginning. At first it was because the team lacked confidence in their estimations, and wanted more frequent checkpoints; now, I suspect everyone is just used to it. Again, it seems to be working fairly well, but I suspect this is project-specific. If we had bigger features to build, two week sprints might not provide the time to get anything done.
• Part-time resources. There's no dedicated QA or doc, and no expectation of ever getting any (I've got three other projects to mind, and QA is by far our most strapped department). I've just been taking whatever handful of project tasks I think I'll have time to work on during a given sprint, taking into account everything else that needs to get done. I feel I'm not really getting whatever benefits come from the methodology.
  
• No team space. No one has really commented on this. We do have a Wiki for virtual artifacts, but there's no physical team area.
  
• Seated scrums, and it's apparently impossible to keep developers from talking in detail about what they're doing. Since it's a small team, this hasn't been a problem most of the time, but as we add members the scrums are going to start getting unwieldy if people can't stick to the "what I did, what I'm doing, what's blocking me" formula.