Let each member add the address of their page on another site, such as Facebook, and show that page's embedded feed on their profile. It takes a Form Designer field and a template change; no module.
Open your own profile's settings (the gear on your profile), and click Form Designer. Add a field:
profile_facebookMembers now have a Facebook page field in their profile settings. See Using the Form Designer.
Get the embed code from the other site, such as Facebook's Page Plugin, and add it to your skin's profile template, using the member's address. In a cloned skin's profile sidebar or header template:
{if !empty($profile_facebook)}
<div class="block">
<h3>Facebook</h3>
<div class="fb-page" data-href="{$profile_facebook|jrCore_entity_string}" data-tabs="timeline" data-width="340"></div>
</div>
{/if}Add the other site's script once, in your skin's footer.tpl or header.tpl, as its instructions say. Wrap it in {literal} ... {/literal}: see {literal}.
The same works for any site that offers an embed by address. Use a cloned skin: see Cloning a Skin.