grep for 'get_entity('  in the whole elgg directory...

Alternatively, start by disabling 3rd party plugins. If the error is gone, you know which plugin is causing the issue and searching for the get_entity line might be easier.

@Andy1966uk

In order to quickly find where this depreciated call is located, you should use Elgg Developer Tools plugin. Activate this plugin and do the following:

1) Turn off Use simple cache (just for now).
2) set Trace level to Warnings.
3) Activate/check Log to the screen.
4) Go to http://www.iracebook.net/groups/profile/42/formula-1

You will see on the page bottom the warning that indicate exactly where this call loctaed
(Something like: WARNING: Deprecated in 1.8: ........... )

A great plugin for developers by the way :-)

ok, y'all that's called "software developers.." ;-)
..this is not called "rocket science" ;-)
it's about as easy as eating american pie....
just goto the elgg lib code for deprecated
and in the function, at the top add :=>

function ..... {

    if (elgg_is_admin_logged_in()) { // no deprecated notice unless Admin is logged in ;-oP 
        return TRUE;
    }
. . .  etc

any volunteers for a pull request to "fix" ?

whatever plugin u are running that is causing this issue go into its start.php and search for get_entities and everywhere in the code change it to elgg_get_entities this will take the errors away, u also have to replace list_entities with elgg_list_entities and Extend_view with elgg_extend_view this will take all visible errors away

I created a ticket, will make a pull some time soon.

http://trac.elgg.org/ticket/4278

i see small typo above ;-)
shud be
if ( ! elgg_is_admin_logged_in..

Well, this issue would be irrelevant if you would have your development environment (and maybe also a test environment, if you can afford it) separated form production development :-)  That is what I always do.

Otherwise, this needs to be fixed anyway - warnings for admins only!