>>64251704 (OP)
There are several, though it depends on whether or not you want to count wildcats. Some are pretty common, like 7mm-06. Some are obscure and require forming your own brass.
> but if theres something thats easily convertable to other calibers
That is a TOTALLY different question. Very few .30-06's will be convertible to anything else without gunsmithing. The fact that some modern guns are modular and let you swap calibers is the exception rather than the rule. 99% of .30-06 will not convert into anything else without gunsmithing.
IMHO there's zero reason to buy a .30-06 because of the cartridge. It's something you might buy because you like the gun, for nostalgic purposes. If you want a .30 cal the baseline standard is a .308. .30-06 isn't appreciably better, but it does require a long action which greatly reduces the number of rifles chambered in it. If .308 won't work for your purposes because of some technical feature like range or power then .30-06 won't really help. Cartridges like 6.5 creedmore or .300 win mag offer significant, tangible, upgrades to .308. Look at those if .308 is inadequate for your needs.