Even the best streaming services that claim to be in HD stream at only about 1 mbps, or 5 to 10 mbps at the most, says Mark Waldrep, president and chief engineer of . That's about the same as a standard DVD disc, which presents video at 4 to 8 mbps.

In comparison, a Blu-ray Disc pumps pixels at up to 36 mbps, says Waldrep. As a result, when you're watching 1977's Star Wars: A New Hope, for example, you can see the grime on C-3PO's golden shell and laugh at Princess Leia's bad makeup job.

One potential roadblock for streaming is that ISPs and wireless carriers attempt to curb bandwidth hogs by throttling speeds and capping downloads. For example, Verizon Wireless charges some of its customers an extra $10 per gigabyte if they . Under a Verizon plan, someone with a big appetite for feature-length movies could see their costs go up--or they could see the quality of their movie streams degrade--toward the end of the month.

[Related: "" and "")