Additional nodes can be specified with the command line or bitcoin.conf option "
addnode=10.0.0.1:8333". This is not guaranteed to open a connection, the other Bitcoin nodes still have to like you and be wanting more connections. IP addresses quickly become obsolete, a large number of Bitcoin users are on dynamic IP addresses or don't run Bitcoin full time.
You can throw something like this into your bitcoin.conf file if you want to attempt connection to your own list of IP addresses in addition to the peer-finding methodology in Bitcoin, which already works quite well.
maxconnections=500
addnode=173.242.112.53
addnode=62.75.216.13
addnode=173.242.112.53
addnode=184.154.36.82
addnode=188.165.213.169
addnode=213.112.48.166
addnode=91.210.181.21
addnode=99.115.228.181
addnode=184.154.36.82
addnode=46.253.203.99
addnode=176.31.159.150
addnode=46.4.121.100
addnode=110.173.227.233
addnode=176.9.56.118
addnode=173.254.18.115
addnode=46.253.203.99
addnode=176.31.159.150
addnode=46.4.121.100
addnode=110.173.227.233
addnode=83.151.21.200
addnode=176.9.56.118
addnode=81.29.3.30
addnode=204.45.253.22
addnode=88.214.194.226
addnode=78.47.229.99
addnode=152.54.8.107
addnode=107.22.234.139
addnode=188.40.93.82
addnode=50.19.225.254
addnode=178.79.147.99
addnode=78.47.187.254
addnode=208.110.73.247
addnode=46.4.148.130
addnode=184.72.73.207
addnode=67.210.248.14
addnode=176.9.130.32
addnode=23.22.18.45
addnode=46.253.195.52
addnode=204.9.55.71
addnode=178.79.154.170
addnode=174.127.101.54
addnode=109.75.183.11
addnode=107.20.229.35
addnode=82.114.105.251
addnode=176.9.26.234
addnode=173.242.112.53
addnode=84.16.67.89
addnode=188.40.77.148
addnode=46.29.248.109
addnode=78.47.16.205
addnode=178.33.50.215
addnode=50.45.128.28
addnode=176.9.135.190
addnode=46.253.203.98
addnode=188.40.82.9
addnode=46.4.121.99
addnode=46.253.195.53
addnode=110.173.227.195
addnode=109.74.195.190
addnode=176.9.91.111
addnode=93.186.32.118
addnode=178.79.130.99
addnode=176.9.142.163
addnode=81.169.165.107
addnode=69.164.218.197
addnode=178.63.100.86
addnode=108.60.141.139
addnode=213.189.52.53
addnode=77.236.98.69
addnode=78.47.187.255
addnode=178.63.15.200
addnode=64.120.173.148
addnode=82.146.47.200
addnode=46.4.90.208
addnode=176.9.5.91
addnode=91.223.77.253
addnode=46.163.78.236
addnode=46.4.13.200
addnode=77.72.0.50
addnode=91.198.211.27
addnode=46.253.195.51
addnode=176.9.130.35
addnode=46.4.74.54
addnode=68.71.141.134
addnode=176.9.104.178
addnode=204.45.253.21
addnode=95.211.41.87
addnode=108.60.208.157
addnode=188.40.131.134
addnode=46.105.108.31
addnode=50.31.135.6
addnode=50.31.135.4
addnode=176.9.56.125
addnode=110.173.227.193
addnode=208.110.68.116
addnode=178.79.155.33
addnode=46.4.148.153
addnode=50.45.128.29
addnode=176.9.0.26
addnode=78.46.200.22
addnode=178.79.168.31
addnode=93.186.32.121
addnode=176.9.130.36
addnode=88.198.111.188
addnode=193.254.190.88
addnode=62.75.185.150
addnode=176.9.18.83
addnode=81.95.121.14
addnode=193.146.190.89
addnode=178.79.155.53
addnode=67.210.248.12
addnode=88.198.23.43
addnode=69.30.224.137
addnode=88.198.16.86
addnode=87.106.84.25
addnode=110.173.226.49
addnode=88.214.193.104
addnode=80.237.180.184
addnode=46.4.121.98
addnode=208.110.68.114
addnode=107.20.142.238
addnode=46.253.195.54
addnode=50.73.45.250
addnode=176.9.122.123
addnode=188.40.92.153
addnode=206.71.179.116
addnode=173.193.21.69
addnode=110.173.227.109
addnode=37.59.68.76
addnode=93.186.32.117
addnode=78.47.246.21
addnode=78.47.103.106
addnode=46.4.96.52
addnode=46.4.115.228
addnode=217.115.11.163
addnode=110.173.227.196
addnode=178.33.83.15
addnode=46.4.147.38
addnode=188.40.68.252
addnode=50.45.128.27
addnode=176.9.130.31
addnode=91.213.175.240
addnode=78.47.187.252
addnode=64.22.103.150
addnode=98.143.152.14
addnode=110.173.227.198
addnode=176.9.91.123
addnode=176.28.11.89
addnode=85.17.51.144
addnode=188.40.91.149
addnode=178.79.170.65
addnode=78.47.162.161
addnode=46.105.119.41
addnode=178.79.178.173
addnode=46.105.123.163
addnode=50.31.135.5
addnode=110.173.227.197
addnode=176.9.91.124
addnode=209.160.27.93
addnode=67.83.108.0
addnode=80.217.129.64
addnode=178.33.50.214
addnode=46.163.74.185
addnode=46.4.124.20
addnode=78.47.12.238
addnode=110.173.227.194
addnode=64.34.179.254
addnode=176.31.157.133
addnode=93.186.32.122
addnode=78.46.212.125
addnode=178.79.177.146
addnode=31.222.176.99
addnode=173.255.204.158
addnode=46.4.121.102
addnode=78.46.49.61
addnode=46.4.115.147
addnode=78.46.63.13
addnode=173.255.194.34
addnode=46.4.73.137
addnode=91.121.157.85
addnode=176.9.42.247
addnode=208.110.68.115
addnode=46.253.195.50
Fallback nodes are listed here:
https://en.bitcoin.it/wiki/Fallback_NodesYou can also grab other's lists of connected IP addresses:
http://blockchain.info/connected-nodeshttp://nodes.bitcoin.st/http://pastehtml.com/view/c7rf4x1gc.rtxtIf you already have another machine that is running and updated, you do not need to connect to the public network at all, your second copy of Bitcoin can connect exclusively to the local machine with the option
connect=192.168.1.100 (whatever the IP address is of the first Bitcoin).
Bitcoin binaries are available at
http://bitcoin.org.