Below are a couple area repeaters that you can tune to:

• WBOYLA’s 145.390(-) repeater in Thurman, IA (Node: 366048)
• KC0VEY’s 443.975(+) PL114.8 repeater in Omaha, NE (Node: 289653)
• WB0GXD’s 442.525(+) PL100.0 repeater in Council Bluffs, IA (Node: 50513)
• WB0QQK’s 443.350(+) PL179.9 repeater in Bellevue, NE (Node: 381309)

Here are a few EchoLink commands:
(Note: These are the “default” codes. Repeater owners can change them!)

To connect to a node just dial the node number on your DTMF keypad
00 Connects to any random node in the EchoLink network
01 Connects to a random node that is a LINK (-L) or a REPEATER (-R)
02 Connects to a random conference room
03 Connects to a random single-user
08 Announces all nodes that are currently connected
09 Reconnects to the last node that connected
# Disconnects the last node that connected
## Disconnects all nodes that are connected
* Plays the ID message of the repeater

There are other commands, such as, connecting by Call Sign, looking up a Call Sign to get its node number, etc. Try doing a Google search for EchoLink commands.