How easy is DSL to install?

There are a few options when it comes to DSL (internal or external DSL 'modem', etc..). It's relitively easy though. Those filters you mention are little 'boxes' (about the size of a vinyl erasor stick). You unplug your phone from the wall, plug the cord into one end of the filter, and the other end of the filter has another phone plug that you put into the wall (it goes between the phone and the jack in the wall).

The hardest part is getting your computer networked. Do you have a NIC (network card) in your system? Then, I'd go with an external DSL modem, which pretty much just plugs into your NIC and with a few minor changes in your networking setup you're good to go. If you don't have a NIC, you can either purchase one (starting at $20 USD) and use that with an external DSL modem, OR you can get an internal dsl modem (if your dsl provider offers those) and it gets installed into your system (similar to a NIC).

They both work well, but internal DSL modems don't have the capability of going as fast as the external ones can go (The limit for internal is like 512kbps (which is more than most people subscribe to as it gets quite expensive higher than that) while external ones can go all the way to 2Mbps). External modems do also have the advantage of working with DSL routers so that you can use more than one PC on the net at a time (if you have a home network for example, or even just two pcs). External ones are more expensive too. A lot of people get a package that gives them 256 up and down stream so both dsl modems will do the trick in that case... Depending on the DSL type (SDSL or ADSL) you can see speeds in combinations like 768Kbps download but 128Kbps upload. Don't forget that you have to get a DSL line 'on top' of your phone line and an ISP on top of that.

Hope that helps a bit...