The Samsung Moment does not use Sprint Mobile Sync, It uses google to sync your contacts, When you set it back up and enter your Google/Gmail account info if your contacts were backed up there then they would automatically sync back to your phone. If you didn't have it set to sync to Google or have not done a contacts to sd card export then your contacts are gone.
Blackberry is a very different question. Depending on the services that you have and whether or not you have a phone from your company or a personal phone, you have a lot of options to sync contacts.
For personal use, depending on the type of Blackberry that you have, most of the newer ones have an option to allow you to sync contacts to webmail accounts like Gmail and Yahoo during the setup of those email accounts on the phone.
For business use, it will likely be best to contact your IT department to find out what solutions are available to you.
The Samsung Seek uses "Sprint Mobile Sync" which is a service included in the plan required for the device. For instructions on how to set it up look on page 142 of the userguide.
NOTE; When using Sprint Mobile Sync always make sure to go to your account page and download a copy(.csv) of your contacts as when a phone using Sprint Mobile Sync is deactivated for whatever reason you WILL lose access to your contacts.
The Samung Seek should have support for Wireless Backup, which does carry a $2 a month fee with it.
If you need to back them up for troubleshooting, a Service Center should be able to back up the contacts on the phone for you before starting any repairs.
The HTC Evo uses Google/Gmail to sync contacts, What you will need to do is sign into your Gmail account page and import the contacts then on the phone go into the Accounts & Sync settings page and select Google>Sync Contacts.
You will have to do it for each gmail/phone separately.
I just got an evo shift and a regular evo 4g. I have lists of contacts saved in my computer one list mine and one list my wifes, how do i put lists to phones???