Here's a list of the few things I was able to modify which make the game feel a bit better. All these are in your config_mp.cfg file which is a hardware config file and should not be considered a VAC bannable offense. That said, change at your own risk! On Windows 7 x64 the file is listed here:
C:\Program Files (x86)\Steam\steamapps\common\call of duty modern warfare 2\players\config_mp.cfg
seta drawLagometer "1" (BTW, you will not see the lagometer if you are the host)
seta com_maxfps "76" (many people use 125 here)
seta cl_maxpackets "77" (many people use 100 here)
seta snaps "30"
Perhaps Regs or someone can find where the details to what all of these mean, I can't find it. I know BashAndSlash had a good one.
And the following will give you a nice easier representation of what the actual ping your getting is. The default is to have 4 bars, each representing 100ms. I changed it to 10 bars, each representing 40ms. If you had 4 bars(dark green) before, you were getting anywhere between 100 - 0 ms ping, 3 bars (light green) you were getting between 200 - 100 ms ping, etc. Now the new way 8 bars means your at about 80 ping, 7 bars means your getting 120 ms ping, etc.
seta cg_ScoresPing_Interval "40"
seta cg_ScoresPing_MaxBars "10"http://www.shaytastic.com/BigShay/files/pingbars.jpg