You can connect a blu-ray drive(USB/E-SATA/ect) to the computer and watch the videos with the right software and hardware power.
A stand alone player may work with a TV capture card, but the quality will suffer lots(because most capture in SD) and any card that can capture HDMI will not work because of copy protection in the player and on the discs.
You could get a external USB/E-SATA(if your laptop has E-SATA) drive to watch Blu Ray's on and it should work fine as long as your laptop has the CPU and video card power to decode it ok. As far as a standalone Blu Ray player you would not really be able to do that very well I would think. You would need a USB capture card and most of the one's I have seen are not HD so the quality would not the best.
doesnt it also require a certain program, which costs money?
Most of the drive's I have seen come with PowerDVD or WinDVD bundled with the drive. Unless you get a OEM witch do not come with software. I have a External USB Blu Ray drive for my Asus Laptop and it works just fine it came with PowerDVD and plays Blu Ray and DVD's with that software.