OK well I have recently become rather unhappy with my hosts service and performance and I will probably look to change hosts in the coming weeks. Now I have read lots of posts in regards to hosting interlinking sites on different IPs or hosts and I was just wondering what sort of effects might occur if I was to change hosts for all my sites...?
I didn't understand your situation completely. I hope you have done a search on this forum before posting this one.. Changing from one host to another will not have any effect on the current serps if its done with care .. (I mean keeping the files crawlable always and not having a huge delay in tranferring files from one to other). Better practice is transfer the whole site contents to new location and then update the name servers.
Here is a post from Matt Cutts. It's a step-by-step of the best way to move to a new host. If you follow those advices, I think you should be safe.
Burta, I changed hosting provider yesterday. The process was almost instantaneous once I repointed the DNS. I'll let you know if it has any impact on the SERPs.
Thanks, I'd appreciate that. And thanks everyone else who has commented so far - I have found the replied very useful.