While the adoption of voice over IP in general and IP PBXs in particular continues, one segment continues to struggle: softphones.Softphones are PC-based applications that provide basic telephony (and more), supposedly obviating the need for a separate phone. One of the major advantages of softphones is price. Since it\u2019s an application that takes advantage of a user\u2019s PC hardware, the hardware portion of the phone price is nonexistent.But users aren\u2019t moving to softphones in droves. Some implementers of VoIP have reported anecdotally that when given a choice, users tend to choose a separate phone much more often than they had anticipated. At least one reason that has been postulated for this slow uptake is simple human nature. We find it natural to talk on a phone, not on a PC.Now we have yet another reason not to use softphones. Some users of softphones were hit quite hard by the recent outbreak of the Sobig.F e-mail worm. And if your PC is taken out of commission, your softphone is out of commission as well.Of course, one could argue that your PC should be protected against e-mail-borne worms and viruses by simply keeping your virus definitions for your anti-virus software up to date. And there\u2019s a lot of validity to this argument. Nevertheless, it\u2019s a fact of life that many companies were hit very hard by this worm, so we\u2019re not expecting miracles in the realm of human behavior anytime soon.We also could argue that having a softphone on the PC makes it a more critical resource. Consequently, users will take updating their anti-virus software religiously as a critical part of being a good corporate citizen. But in the interim, the possible instability of PCs due to various viruses and worms certainly will not help the softphone market.By the way, Steve and Joanie Wexler have been covering the implications of Sobig on network infrastructure in Network World\u2019s Wide Area Networking newsletter. Check out the archives there for an interesting case study of a university that proactively upgraded its e-mail system to be ready for this type of attack. This is the type of infrastructure that will be needed for successful deployment of softphones.